Big Delta AP Weather Records (USW00026415)
Record envelope, standing records and threshold days for Big Delta AP (USW00026415), Alaska, United States, with 110 years of record.
Key Facts for Big Delta AP
- Big Delta AP (USW00026415) is a weather station in Alaska, United States at 63.99 latitude and -145.72 longitude, 388 m (1,273 ft) above sea level.
- The station reports from 1917 to 2026, 110 years of record.
- 1,464 records set at Big Delta AP still stand.
- Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
- Big Delta AP set a daily record precipitation of 12.7 mm (0.5 in) on 5 September 2026 (provisional).
Provisional Records
Records set in the last 60 days are provisional until they clear the revision window.
About the Station
- Location: Alaska, United States, 63.99 latitude, -145.72 longitude.
- Elevation: 388 m (1,273 ft).
- Period of record: 1917 to 2026, 110 years.
- Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
4 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 12.2 C (54.0 F) | -52.8 C (-63.0 F) | 7.2 C (45.0 F) | -44.4 C (-47.9 F) |
| Feb | 10.6 C (51.1 F) | -51.1 C (-60.0 F) | -3.3 C (26.1 F) | -43.3 C (-45.9 F) |
| Mar | 14.4 C (57.9 F) | -45.0 C (-49.0 F) | -0.6 C (30.9 F) | -41.1 C (-42.0 F) |
| Apr | 22.2 C (72.0 F) | -38.3 C (-36.9 F) | 12.2 C (54.0 F) | -18.9 C (-2.0 F) |
| May | 32.2 C (90.0 F) | -18.3 C (-0.9 F) | 17.8 C (64.0 F) | -1.1 C (30.0 F) |
| Jun | 33.3 C (91.9 F) | -3.3 C (26.1 F) | 25.0 C (77.0 F) | 2.8 C (37.0 F) |
| Jul | 32.8 C (91.0 F) | 0.0 C (32.0 F) | 27.2 C (81.0 F) | 5.0 C (41.0 F) |
| Aug | 32.2 C (90.0 F) | -5.6 C (21.9 F) | 26.1 C (79.0 F) | 3.3 C (37.9 F) |
| Sep | 26.1 C (79.0 F) | -18.9 C (-2.0 F) | 17.8 C (64.0 F) | -3.3 C (26.1 F) |
| Oct | 23.3 C (73.9 F) | -39.4 C (-38.9 F) | 9.4 C (48.9 F) | -9.4 C (15.1 F) |
| Nov | 11.1 C (52.0 F) | -43.9 C (-47.0 F) | n/a | n/a |
| Dec | 12.8 C (55.0 F) | -52.2 C (-62.0 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1919 | 7 |
| 1920 | 13 |
| 1937 | 1 |
| 1940 | 3 |
| 1941 | 17 |
| 1942 | 19 |
| 1943 | 18 |
| 1944 | 19 |
| 1945 | 21 |
| 1946 | 16 |
| 1947 | 37 |
| 1948 | 26 |
| 1949 | 25 |
| 1950 | 15 |
| 1951 | 14 |
| 1952 | 20 |
| 1953 | 7 |
| 1954 | 14 |
| 1955 | 6 |
| 1956 | 25 |
| 1957 | 21 |
| 1958 | 21 |
| 1959 | 17 |
| 1960 | 19 |
| 1961 | 32 |
| 1962 | 10 |
| 1963 | 19 |
| 1964 | 35 |
| 1965 | 34 |
| 1966 | 9 |
| 1967 | 12 |
| 1968 | 17 |
| 1969 | 45 |
| 1970 | 20 |
| 1971 | 25 |
| 1972 | 18 |
| 1973 | 10 |
| 1974 | 25 |
| 1975 | 43 |
| 1976 | 21 |
| 1977 | 16 |
| 1978 | 6 |
| 1979 | 27 |
| 1980 | 27 |
| 1981 | 25 |
| 1982 | 17 |
| 1983 | 14 |
| 1984 | 7 |
| 1985 | 26 |
| 1986 | 15 |
| 1987 | 7 |
| 1988 | 10 |
| 1989 | 28 |
| 1990 | 14 |
| 1991 | 9 |
| 1992 | 23 |
| 1993 | 11 |
| 1994 | 25 |
| 1995 | 24 |
| 1996 | 5 |
| 1997 | 13 |
| 1998 | 8 |
| 1999 | 16 |
| 2000 | 11 |
| 2001 | 9 |
| 2002 | 18 |
| 2003 | 29 |
| 2004 | 9 |
| 2005 | 11 |
| 2006 | 8 |
| 2007 | 6 |
| 2008 | 9 |
| 2009 | 17 |
| 2010 | 4 |
| 2011 | 17 |
| 2012 | 2 |
| 2013 | 35 |
| 2014 | 12 |
| 2015 | 13 |
| 2016 | 9 |
| 2017 | 3 |
| 2018 | 11 |
| 2019 | 24 |
| 2020 | 2 |
| 2021 | 10 |
| 2022 | 8 |
| 2023 | 6 |
| 2024 | 11 |
| 2025 | 11 |
| 2026 | 10 |
All-Time Record Progression
5 new records| Date | Kind | Detail |
|---|---|---|
| 1975-01-06 | Record low maximum temperature | Record low maximum temperature -48.3 C (-54.9 F) |
| 1981-10-18 | Record daily snowfall | Record daily snowfall 26.4 cm (10.4 in) |
| 1999-08-04 | Record high minimum temperature | Record high minimum temperature 21.1 C (70.0 F) |
| 2008-07-28 | Record daily precipitation | Record daily precipitation 57.7 mm (2.3 in) |
| 2024-08-06 | Record high minimum temperature | Record high minimum temperature 21.7 C (71.1 F) |
Wettest Day of Each Month
Jul: 57.7 mm (2.3 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 18.5 mm (0.7 in) | 19 January 1957 |
| Feb | 15.0 mm (0.6 in) | 11 February 1996 |
| Mar | 13.5 mm (0.5 in) | 18 March 1995 |
| Apr | 23.9 mm (0.9 in) | 29 April 1963 |
| May | 29.5 mm (1.2 in) | 28 May 1962 |
| Jun | 54.4 mm (2.1 in) | 6 June 1943 |
| Jul | 57.7 mm (2.3 in) | 28 July 2008 |
| Aug | 34.0 mm (1.3 in) | 14 August 1995 |
| Sep | 36.6 mm (1.4 in) | 10 September 1990 |
| Oct | 24.9 mm (1.0 in) | 28 October 2010 |
| Nov | 22.9 mm (0.9 in) | 1 November 1919 |
| Dec | 21.6 mm (0.9 in) | 26 December 2021 |
Period of Record Coverage
1917 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1917 | 30 | 8% | No |
| 1919 | 206 | 56% | No |
| 1920 | 115 | 31% | No |
| 1937 | 28 | 8% | No |
| 1941 | 271 | 74% | No |
| 1942 | 332 | 91% | Yes |
| 1943 | 364 | 100% | Yes |
| 1944 | 355 | 97% | Yes |
| 1945 | 357 | 98% | Yes |
| 1946 | 363 | 99% | Yes |
| 1947 | 363 | 99% | Yes |
| 1948 | 366 | 100% | Yes |
| 1949 | 365 | 100% | Yes |
| 1950 | 365 | 100% | Yes |
| 1951 | 365 | 100% | Yes |
| 1952 | 366 | 100% | Yes |
| 1953 | 365 | 100% | Yes |
| 1954 | 364 | 100% | Yes |
| 1955 | 365 | 100% | Yes |
| 1956 | 366 | 100% | Yes |
| 1957 | 365 | 100% | Yes |
| 1958 | 365 | 100% | Yes |
| 1959 | 365 | 100% | Yes |
| 1960 | 366 | 100% | Yes |
| 1961 | 365 | 100% | Yes |
| 1962 | 365 | 100% | Yes |
| 1963 | 365 | 100% | Yes |
| 1964 | 364 | 99% | Yes |
| 1965 | 365 | 100% | Yes |
| 1966 | 365 | 100% | Yes |
| 1967 | 365 | 100% | Yes |
| 1968 | 366 | 100% | Yes |
| 1969 | 365 | 100% | Yes |
| 1970 | 365 | 100% | Yes |
| 1971 | 365 | 100% | Yes |
| 1972 | 366 | 100% | Yes |
| 1973 | 365 | 100% | Yes |
| 1974 | 365 | 100% | Yes |
| 1975 | 364 | 100% | Yes |
| 1976 | 366 | 100% | Yes |
| 1977 | 365 | 100% | Yes |
| 1978 | 364 | 100% | Yes |
| 1979 | 365 | 100% | Yes |
| 1980 | 366 | 100% | Yes |
| 1981 | 365 | 100% | Yes |
| 1982 | 365 | 100% | Yes |
| 1983 | 365 | 100% | Yes |
| 1984 | 366 | 100% | Yes |
| 1985 | 365 | 100% | Yes |
| 1986 | 365 | 100% | Yes |
| 1987 | 365 | 100% | Yes |
| 1988 | 365 | 100% | Yes |
| 1989 | 363 | 99% | Yes |
| 1990 | 272 | 75% | No |
| 1991 | 259 | 71% | No |
| 1992 | 263 | 72% | No |
| 1993 | 309 | 85% | No |
| 1994 | 365 | 100% | Yes |
| 1995 | 365 | 100% | Yes |
| 1996 | 363 | 99% | Yes |
| 1997 | 363 | 99% | Yes |
| 1998 | 364 | 100% | Yes |
| 1999 | 364 | 100% | Yes |
| 2000 | 366 | 100% | Yes |
| 2001 | 365 | 100% | Yes |
| 2002 | 365 | 100% | Yes |
| 2003 | 365 | 100% | Yes |
| 2004 | 366 | 100% | Yes |
| 2005 | 364 | 100% | Yes |
| 2006 | 365 | 100% | Yes |
| 2007 | 364 | 100% | Yes |
| 2008 | 364 | 99% | Yes |
| 2009 | 359 | 98% | Yes |
| 2010 | 365 | 100% | Yes |
| 2011 | 365 | 100% | Yes |
| 2012 | 366 | 100% | Yes |
| 2013 | 342 | 94% | Yes |
| 2014 | 365 | 100% | Yes |
| 2015 | 365 | 100% | Yes |
| 2016 | 366 | 100% | Yes |
| 2017 | 365 | 100% | Yes |
| 2018 | 354 | 97% | Yes |
| 2019 | 365 | 100% | Yes |
| 2020 | 366 | 100% | Yes |
| 2021 | 363 | 99% | Yes |
| 2022 | 364 | 100% | Yes |
| 2023 | 365 | 100% | Yes |
| 2024 | 364 | 99% | Yes |
| 2025 | 351 | 96% | Yes |
| 2026 | 284 | 78% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 5 September 2026 | Big Delta AP, US | daily rain (Provisional) | 12.7 mm (0.5 in) | 1.5 mm (0.06 in) | 61 years | 20 of 100 (Routine) |
| 25 August 2026 | Big Delta AP, US | daily rain (Provisional) | 16.3 mm (0.6 in) | 5.1 mm (0.20 in) | 9 years | 20 of 100 (Routine) |
| 15 August 2026 | Big Delta AP, US | daily rain | 20.6 mm (0.8 in) | 5.4 mm (0.21 in) | 68 years | 20 of 100 (Routine) |
| 14 August 2026 | Big Delta AP, US | daily high min | 15.0 C (59.0 F) | 0.6 C (1.1 F) | 23 years | 17 of 100 (Routine) |
| 24 July 2026 | Big Delta AP, US | daily low max | 10.6 C (51.1 F) | 0.5 C (0.9 F) | 60 years | 29 of 100 (Routine) |
| 9 July 2026 | Big Delta AP, US | daily rain | 27.2 mm (1.1 in) | 3.3 mm (0.13 in) | 72 years | 35 of 100 (Notable) |
| 9 July 2026 | Big Delta AP, US | daily low max (Tie) | 12.2 C (54.0 F) | tie | 68 years | 7 of 100 (Routine) |
| 21 March 2026 | Big Delta AP, US | daily low min | -32.2 C (-26.0 F) | 3.3 C (5.9 F) | 64 years | 32 of 100 (Routine) |
| 19 March 2026 | Big Delta AP, US | daily low max | -17.8 C (0.0 F) | 0.6 C (1.1 F) | 60 years | 28 of 100 (Routine) |
| 18 March 2026 | Big Delta AP, US | daily low min | -37.8 C (-36.0 F) | 0.6 C (1.1 F) | 67 years | 30 of 100 (Routine) |
| 17 March 2026 | Big Delta AP, US | daily low max | -21.1 C (-6.0 F) | 0.5 C (0.9 F) | 60 years | 28 of 100 (Routine) |
| 28 February 2026 | Big Delta AP, US | daily low min | -42.8 C (-45.0 F) | 5.0 C (9.0 F) | 72 years | 35 of 100 (Notable) |
| 27 February 2026 | Big Delta AP, US | daily low min | -43.3 C (-45.9 F) | 2.7 C (4.9 F) | 72 years | 33 of 100 (Routine) |
| 27 February 2026 | Big Delta AP, US | daily low max | -27.2 C (-17.0 F) | 2.8 C (5.0 F) | 40 years | 24 of 100 (Routine) |
| 26 February 2026 | Big Delta AP, US | daily low max | -27.8 C (-18.0 F) | 1.7 C (3.1 F) | 72 years | 32 of 100 (Routine) |
| 23 February 2026 | Big Delta AP, US | daily rain | 5.1 mm (0.20 in) | 0.8 mm (0.03 in) | 11 years | 17 of 100 (Routine) |
| 8 November 2025 | Big Delta AP, US | daily rain | 3.6 mm (0.14 in) | 0.6 mm (0.02 in) | 38 years | 20 of 100 (Routine) |
| 20 July 2025 | Big Delta AP, US | daily high min (Tie) | 15.6 C (60.1 F) | tie | 24 years | 4 of 100 (Routine) |
| 18 July 2025 | Big Delta AP, US | daily high max (Tie) | 26.1 C (79.0 F) | tie | 32 years | 4 of 100 (Routine) |
| 7 July 2025 | Big Delta AP, US | daily rain | 31.5 mm (1.2 in) | 13.2 mm (0.5 in) | 58 years | 46 of 100 (Notable) |
Climate Trend
80 complete years, 1943 to 2024| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1943 | -1.3 C | +0.61 C |
| 1944 | -1.0 C | +0.90 C |
| 1945 | -2.6 C | -0.67 C |
| 1946 | -3.2 C | -1.30 C |
| 1947 | -1.6 C | +0.35 C |
| 1948 | -4.4 C | -2.48 C |
| 1949 | -2.7 C | -0.76 C |
| 1950 | -3.1 C | -1.16 C |
| 1951 | -3.1 C | -1.20 C |
| 1952 | -2.0 C | -0.06 C |
| 1953 | -1.5 C | +0.48 C |
| 1954 | -3.0 C | -1.03 C |
| 1955 | -3.8 C | -1.82 C |
| 1956 | -5.0 C | -3.02 C |
| 1957 | -0.7 C | +1.29 C |
| 1958 | -1.2 C | +0.74 C |
| 1959 | -3.4 C | -1.50 C |
| 1960 | -1.5 C | +0.42 C |
| 1961 | -4.3 C | -2.34 C |
| 1962 | -2.0 C | -0.04 C |
| 1963 | -2.1 C | -0.15 C |
| 1964 | -3.9 C | -1.96 C |
| 1965 | -3.0 C | -1.05 C |
| 1966 | -4.0 C | -2.09 C |
| 1967 | -2.0 C | -0.05 C |
| 1968 | -2.3 C | -0.38 C |
| 1969 | -1.5 C | +0.41 C |
| 1970 | -2.2 C | -0.26 C |
| 1971 | -4.6 C | -2.68 C |
| 1972 | -4.4 C | -2.47 C |
| 1973 | -3.0 C | -1.09 C |
| 1974 | -3.9 C | -1.98 C |
| 1975 | -4.0 C | -2.05 C |
| 1976 | -1.1 C | +0.89 C |
| 1977 | -1.0 C | +0.98 C |
| 1978 | 0.4 C | +2.37 C |
| 1979 | -1.3 C | +0.68 C |
| 1980 | -0.8 C | +1.12 C |
| 1981 | 0.6 C | +2.58 C |
| 1982 | -3.7 C | -1.71 C |
| 1983 | -2.6 C | -0.62 C |
| 1984 | -2.6 C | -0.64 C |
| 1985 | -2.2 C | -0.22 C |
| 1986 | -1.7 C | +0.27 C |
| 1987 | -0.6 C | +1.33 C |
| 1988 | -1.2 C | +0.77 C |
| 1989 | -2.2 C | -0.23 C |
| 1990 | -2.9 C | -0.91 C |
| 1991 | -1.5 C | +0.41 C |
| 1992 | -2.5 C | -0.53 C |
| 1994 | -1.8 C | +0.11 C |
| 1995 | -0.9 C | +1.03 C |
| 1996 | -3.5 C | -1.56 C |
| 1997 | -0.6 C | +1.35 C |
| 1998 | -1.0 C | +0.99 C |
| 1999 | -3.5 C | -1.60 C |
| 2000 | -1.0 C | +0.99 C |
| 2001 | -1.1 C | +0.87 C |
| 2002 | 0.1 C | +2.04 C |
| 2003 | -0.8 C | +1.15 C |
| 2004 | -0.5 C | +1.43 C |
| 2005 | -0.1 C | +1.82 C |
| 2006 | -2.2 C | -0.27 C |
| 2007 | -1.4 C | +0.50 C |
| 2008 | -3.1 C | -1.19 C |
| 2009 | -1.5 C | +0.43 C |
| 2010 | -1.1 C | +0.86 C |
| 2011 | -1.9 C | +0.03 C |
| 2012 | -3.3 C | -1.34 C |
| 2013 | -1.7 C | +0.29 C |
| 2014 | -0.1 C | +1.80 C |
| 2015 | -0.2 C | +1.73 C |
| 2016 | 1.2 C | +3.19 C |
| 2017 | -0.5 C | +1.49 C |
| 2019 | 1.0 C | +2.94 C |
| 2020 | -2.3 C | -0.36 C |
| 2021 | -2.1 C | -0.15 C |
| 2022 | -1.1 C | +0.86 C |
| 2023 | -1.0 C | +0.99 C |
| 2024 | -0.7 C | +1.28 C |
The annual mean temperature here has risen by 0.3 C (0.1 to 0.4) per decade over 1943 to 2024. In Fahrenheit: 0.5 F (0.3 to 0.7) per decade. The slope is a straight line fitted to 80 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.3 C (0.1 to 0.4) per decade | 0.5 F (0.3 to 0.7) per decade | 1943 to 2024 | 80 | Rise |
| Mean daily maximum | 0.2 C (0.1 to 0.3) per decade | 0.4 F (0.2 to 0.6) per decade | 1943 to 2024 | 80 | Rise |
| Mean daily minimum | 0.3 C (0.2 to 0.4) per decade | 0.5 F (0.3 to 0.8) per decade | 1943 to 2024 | 80 | Rise |
A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.
Extremes by Year
1917 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 33.3 C (91.9 F) | 1969 | 29.4 C (84.9 F) | 90 |
| Coldest night (TNn) | -52.8 C (-63.0 F) | 1947 | -43.8 C (-46.9 F) | 90 |
| Wettest day (Rx1day) | 57.7 mm (2.3 in) | 2008 | 24.9 mm (1.0 in) | 90 |
| Wettest five days (Rx5day) | 103.4 mm (4.1 in) | 2008 | 42.7 mm (1.7 in) | 88 |
| Longest dry spell (CDD) | 109 days | 1980 | 45 days | 88 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1917 | 26.7 C (80.1 F) |
| 1919 | 31.7 C (89.1 F) |
| 1920 | 8.9 C (48.0 F) |
| 1937 | 16.1 C (61.0 F) |
| 1940 | n/a |
| 1941 | 27.8 C (82.0 F) |
| 1942 | 30.6 C (87.1 F) |
| 1943 | 26.7 C (80.1 F) |
| 1944 | 26.7 C (80.1 F) |
| 1945 | 24.4 C (75.9 F) |
| 1946 | 29.4 C (84.9 F) |
| 1947 | 32.2 C (90.0 F) |
| 1948 | 31.1 C (88.0 F) |
| 1949 | 27.8 C (82.0 F) |
| 1950 | 30.0 C (86.0 F) |
| 1951 | 31.1 C (88.0 F) |
| 1952 | 27.8 C (82.0 F) |
| 1953 | 30.0 C (86.0 F) |
| 1954 | 27.8 C (82.0 F) |
| 1955 | 32.2 C (90.0 F) |
| 1956 | 28.3 C (82.9 F) |
| 1957 | 30.6 C (87.1 F) |
| 1958 | 32.8 C (91.0 F) |
| 1959 | 29.4 C (84.9 F) |
| 1960 | 30.0 C (86.0 F) |
| 1961 | 27.8 C (82.0 F) |
| 1962 | 29.4 C (84.9 F) |
| 1963 | 27.8 C (82.0 F) |
| 1964 | 26.7 C (80.1 F) |
| 1965 | 27.2 C (81.0 F) |
| 1966 | 26.1 C (79.0 F) |
| 1967 | 30.6 C (87.1 F) |
| 1968 | 28.9 C (84.0 F) |
| 1969 | 33.3 C (91.9 F) |
| 1970 | 28.9 C (84.0 F) |
| 1971 | 29.4 C (84.9 F) |
| 1972 | 30.6 C (87.1 F) |
| 1973 | 27.8 C (82.0 F) |
| 1974 | 29.4 C (84.9 F) |
| 1975 | 31.1 C (88.0 F) |
| 1976 | 30.6 C (87.1 F) |
| 1977 | 31.1 C (88.0 F) |
| 1978 | 29.4 C (84.9 F) |
| 1979 | 29.4 C (84.9 F) |
| 1980 | 30.0 C (86.0 F) |
| 1981 | 28.3 C (82.9 F) |
| 1982 | 28.9 C (84.0 F) |
| 1983 | 30.0 C (86.0 F) |
| 1984 | 24.4 C (75.9 F) |
| 1985 | 26.1 C (79.0 F) |
| 1986 | 28.9 C (84.0 F) |
| 1987 | 28.9 C (84.0 F) |
| 1988 | 26.1 C (79.0 F) |
| 1989 | 28.3 C (82.9 F) |
| 1990 | 30.0 C (86.0 F) |
| 1991 | 32.2 C (90.0 F) |
| 1992 | 30.6 C (87.1 F) |
| 1993 | 30.6 C (87.1 F) |
| 1994 | 32.2 C (90.0 F) |
| 1995 | 28.9 C (84.0 F) |
| 1996 | 27.2 C (81.0 F) |
| 1997 | 28.9 C (84.0 F) |
| 1998 | 28.3 C (82.9 F) |
| 1999 | 29.4 C (84.9 F) |
| 2000 | 26.7 C (80.1 F) |
| 2001 | 26.7 C (80.1 F) |
| 2002 | 27.8 C (82.0 F) |
| 2003 | 29.4 C (84.9 F) |
| 2004 | 31.1 C (88.0 F) |
| 2005 | 29.4 C (84.9 F) |
| 2006 | 26.7 C (80.1 F) |
| 2007 | 27.2 C (81.0 F) |
| 2008 | 27.8 C (82.0 F) |
| 2009 | 30.6 C (87.1 F) |
| 2010 | 30.0 C (86.0 F) |
| 2011 | 28.3 C (82.9 F) |
| 2012 | 28.3 C (82.9 F) |
| 2013 | 32.2 C (90.0 F) |
| 2014 | 27.2 C (81.0 F) |
| 2015 | 30.6 C (87.1 F) |
| 2016 | 29.4 C (84.9 F) |
| 2017 | 31.1 C (88.0 F) |
| 2018 | 30.0 C (86.0 F) |
| 2019 | 31.1 C (88.0 F) |
| 2020 | 26.1 C (79.0 F) |
| 2021 | 28.9 C (84.0 F) |
| 2022 | 29.4 C (84.9 F) |
| 2023 | 30.6 C (87.1 F) |
| 2024 | 30.0 C (86.0 F) |
| 2025 | 28.9 C (84.0 F) |
| 2026 | 27.2 C (81.0 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1917 | n/a |
| 1919 | -43.3 C (-45.9 F) |
| 1920 | -51.1 C (-60.0 F) |
| 1937 | -4.4 C (24.1 F) |
| 1940 | -34.4 C (-29.9 F) |
| 1941 | -50.6 C (-59.1 F) |
| 1942 | -46.7 C (-52.1 F) |
| 1943 | -46.1 C (-51.0 F) |
| 1944 | -41.1 C (-42.0 F) |
| 1945 | -40.0 C (-40.0 F) |
| 1946 | -52.2 C (-62.0 F) |
| 1947 | -52.8 C (-63.0 F) |
| 1948 | -42.2 C (-44.0 F) |
| 1949 | -43.3 C (-45.9 F) |
| 1950 | -46.1 C (-51.0 F) |
| 1951 | -46.1 C (-51.0 F) |
| 1952 | -46.7 C (-52.1 F) |
| 1953 | -45.6 C (-50.1 F) |
| 1954 | -44.4 C (-47.9 F) |
| 1955 | -43.3 C (-45.9 F) |
| 1956 | -45.6 C (-50.1 F) |
| 1957 | -45.6 C (-50.1 F) |
| 1958 | -42.2 C (-44.0 F) |
| 1959 | -42.8 C (-45.0 F) |
| 1960 | -41.7 C (-43.1 F) |
| 1961 | -51.7 C (-61.1 F) |
| 1962 | -43.9 C (-47.0 F) |
| 1963 | -44.4 C (-47.9 F) |
| 1964 | -51.1 C (-60.0 F) |
| 1965 | -48.9 C (-56.0 F) |
| 1966 | -45.0 C (-49.0 F) |
| 1967 | -42.8 C (-45.0 F) |
| 1968 | -46.1 C (-51.0 F) |
| 1969 | -46.7 C (-52.1 F) |
| 1970 | -41.7 C (-43.1 F) |
| 1971 | -50.0 C (-58.0 F) |
| 1972 | -47.2 C (-53.0 F) |
| 1973 | -47.8 C (-54.0 F) |
| 1974 | -44.4 C (-47.9 F) |
| 1975 | -50.6 C (-59.1 F) |
| 1976 | -43.3 C (-45.9 F) |
| 1977 | -42.2 C (-44.0 F) |
| 1978 | -34.4 C (-29.9 F) |
| 1979 | -46.7 C (-52.1 F) |
| 1980 | -47.8 C (-54.0 F) |
| 1981 | -41.7 C (-43.1 F) |
| 1982 | -45.6 C (-50.1 F) |
| 1983 | -46.7 C (-52.1 F) |
| 1984 | -42.2 C (-44.0 F) |
| 1985 | -42.2 C (-44.0 F) |
| 1986 | -43.9 C (-47.0 F) |
| 1987 | -37.2 C (-35.0 F) |
| 1988 | -36.1 C (-33.0 F) |
| 1989 | -50.6 C (-59.1 F) |
| 1990 | -43.3 C (-45.9 F) |
| 1991 | -47.2 C (-53.0 F) |
| 1992 | -40.0 C (-40.0 F) |
| 1993 | -46.1 C (-51.0 F) |
| 1994 | -43.3 C (-45.9 F) |
| 1995 | -42.8 C (-45.0 F) |
| 1996 | -44.4 C (-47.9 F) |
| 1997 | -46.7 C (-52.1 F) |
| 1998 | -45.0 C (-49.0 F) |
| 1999 | -46.1 C (-51.0 F) |
| 2000 | -42.2 C (-44.0 F) |
| 2001 | -41.1 C (-42.0 F) |
| 2002 | -39.4 C (-38.9 F) |
| 2003 | -36.1 C (-33.0 F) |
| 2004 | -45.6 C (-50.1 F) |
| 2005 | -43.9 C (-47.0 F) |
| 2006 | -41.7 C (-43.1 F) |
| 2007 | -40.6 C (-41.1 F) |
| 2008 | -42.8 C (-45.0 F) |
| 2009 | -43.9 C (-47.0 F) |
| 2010 | -41.1 C (-42.0 F) |
| 2011 | -40.6 C (-41.1 F) |
| 2012 | -45.6 C (-50.1 F) |
| 2013 | -44.4 C (-47.9 F) |
| 2014 | -37.7 C (-35.9 F) |
| 2015 | -42.7 C (-44.9 F) |
| 2016 | -35.5 C (-31.9 F) |
| 2017 | -43.8 C (-46.8 F) |
| 2018 | -34.3 C (-29.7 F) |
| 2019 | -40.5 C (-40.9 F) |
| 2020 | -39.3 C (-38.7 F) |
| 2021 | -39.3 C (-38.7 F) |
| 2022 | -39.3 C (-38.7 F) |
| 2023 | -33.2 C (-27.8 F) |
| 2024 | -44.9 C (-48.8 F) |
| 2025 | -43.3 C (-45.9 F) |
| 2026 | -44.4 C (-47.9 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1917 | n/a |
| 1919 | 22.9 mm (0.9 in) |
| 1920 | 5.1 mm (0.20 in) |
| 1937 | 16.5 mm (0.6 in) |
| 1940 | 10.7 mm (0.4 in) |
| 1941 | 26.2 mm (1.0 in) |
| 1942 | 31.2 mm (1.2 in) |
| 1943 | 54.4 mm (2.1 in) |
| 1944 | 36.6 mm (1.4 in) |
| 1945 | 31.2 mm (1.2 in) |
| 1946 | 49.3 mm (1.9 in) |
| 1947 | 18.0 mm (0.7 in) |
| 1948 | 34.3 mm (1.4 in) |
| 1949 | 25.7 mm (1.0 in) |
| 1950 | 24.9 mm (1.0 in) |
| 1951 | 17.3 mm (0.7 in) |
| 1952 | 34.0 mm (1.3 in) |
| 1953 | 32.8 mm (1.3 in) |
| 1954 | 46.2 mm (1.8 in) |
| 1955 | 32.5 mm (1.3 in) |
| 1956 | 43.2 mm (1.7 in) |
| 1957 | 19.1 mm (0.8 in) |
| 1958 | 17.0 mm (0.7 in) |
| 1959 | 26.7 mm (1.1 in) |
| 1960 | 21.1 mm (0.8 in) |
| 1961 | 34.0 mm (1.3 in) |
| 1962 | 29.5 mm (1.2 in) |
| 1963 | 23.9 mm (0.9 in) |
| 1964 | 24.1 mm (0.9 in) |
| 1965 | 28.2 mm (1.1 in) |
| 1966 | 23.9 mm (0.9 in) |
| 1967 | 29.7 mm (1.2 in) |
| 1968 | 19.6 mm (0.8 in) |
| 1969 | 11.4 mm (0.4 in) |
| 1970 | 12.2 mm (0.5 in) |
| 1971 | 11.7 mm (0.5 in) |
| 1972 | 26.4 mm (1.0 in) |
| 1973 | 25.1 mm (1.0 in) |
| 1974 | 18.3 mm (0.7 in) |
| 1975 | 52.3 mm (2.1 in) |
| 1976 | 40.4 mm (1.6 in) |
| 1977 | 18.8 mm (0.7 in) |
| 1978 | 14.7 mm (0.6 in) |
| 1979 | 28.4 mm (1.1 in) |
| 1980 | 20.8 mm (0.8 in) |
| 1981 | 16.8 mm (0.7 in) |
| 1982 | 23.9 mm (0.9 in) |
| 1983 | 30.0 mm (1.2 in) |
| 1984 | 43.9 mm (1.7 in) |
| 1985 | 24.1 mm (0.9 in) |
| 1986 | 26.9 mm (1.1 in) |
| 1987 | 27.9 mm (1.1 in) |
| 1988 | 23.4 mm (0.9 in) |
| 1989 | 42.4 mm (1.7 in) |
| 1990 | 36.6 mm (1.4 in) |
| 1991 | 21.3 mm (0.8 in) |
| 1992 | 25.4 mm (1.0 in) |
| 1993 | 22.9 mm (0.9 in) |
| 1994 | 11.2 mm (0.4 in) |
| 1995 | 43.4 mm (1.7 in) |
| 1996 | 25.1 mm (1.0 in) |
| 1997 | 18.3 mm (0.7 in) |
| 1998 | 46.0 mm (1.8 in) |
| 1999 | 21.3 mm (0.8 in) |
| 2000 | 21.3 mm (0.8 in) |
| 2001 | 19.3 mm (0.8 in) |
| 2002 | 27.4 mm (1.1 in) |
| 2003 | 27.2 mm (1.1 in) |
| 2004 | 21.3 mm (0.8 in) |
| 2005 | 15.0 mm (0.6 in) |
| 2006 | 51.3 mm (2.0 in) |
| 2007 | 31.8 mm (1.3 in) |
| 2008 | 57.7 mm (2.3 in) |
| 2009 | 26.2 mm (1.0 in) |
| 2010 | 24.9 mm (1.0 in) |
| 2011 | 25.7 mm (1.0 in) |
| 2012 | 15.5 mm (0.6 in) |
| 2013 | 15.5 mm (0.6 in) |
| 2014 | 40.6 mm (1.6 in) |
| 2015 | 23.6 mm (0.9 in) |
| 2016 | 20.6 mm (0.8 in) |
| 2017 | 22.9 mm (0.9 in) |
| 2018 | 24.1 mm (0.9 in) |
| 2019 | 24.1 mm (0.9 in) |
| 2020 | 35.1 mm (1.4 in) |
| 2021 | 21.6 mm (0.9 in) |
| 2022 | 24.4 mm (1.0 in) |
| 2023 | 13.5 mm (0.5 in) |
| 2024 | 18.3 mm (0.7 in) |
| 2025 | 31.5 mm (1.2 in) |
| 2026 | 27.2 mm (1.1 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1917 | n/a |
| 1919 | n/a |
| 1920 | n/a |
| 1937 | 37.8 mm (1.5 in) |
| 1940 | 10.7 mm (0.4 in) |
| 1941 | 55.2 mm (2.2 in) |
| 1942 | 31.2 mm (1.2 in) |
| 1943 | 72.7 mm (2.9 in) |
| 1944 | 43.3 mm (1.7 in) |
| 1945 | 65.0 mm (2.6 in) |
| 1946 | 50.1 mm (2.0 in) |
| 1947 | 29.2 mm (1.1 in) |
| 1948 | 41.6 mm (1.6 in) |
| 1949 | 74.2 mm (2.9 in) |
| 1950 | 46.9 mm (1.8 in) |
| 1951 | 29.5 mm (1.2 in) |
| 1952 | 59.1 mm (2.3 in) |
| 1953 | 42.7 mm (1.7 in) |
| 1954 | 69.5 mm (2.7 in) |
| 1955 | 49.3 mm (1.9 in) |
| 1956 | 70.9 mm (2.8 in) |
| 1957 | 22.6 mm (0.9 in) |
| 1958 | 23.1 mm (0.9 in) |
| 1959 | 39.4 mm (1.6 in) |
| 1960 | 48.3 mm (1.9 in) |
| 1961 | 100.0 mm (3.9 in) |
| 1962 | 38.2 mm (1.5 in) |
| 1963 | 46.8 mm (1.8 in) |
| 1964 | 42.6 mm (1.7 in) |
| 1965 | 41.4 mm (1.6 in) |
| 1966 | 25.9 mm (1.0 in) |
| 1967 | 53.8 mm (2.1 in) |
| 1968 | 34.9 mm (1.4 in) |
| 1969 | 34.1 mm (1.3 in) |
| 1970 | 19.6 mm (0.8 in) |
| 1971 | 19.1 mm (0.8 in) |
| 1972 | 37.6 mm (1.5 in) |
| 1973 | 51.7 mm (2.0 in) |
| 1974 | 33.8 mm (1.3 in) |
| 1975 | 80.2 mm (3.2 in) |
| 1976 | 58.5 mm (2.3 in) |
| 1977 | 37.4 mm (1.5 in) |
| 1978 | 23.4 mm (0.9 in) |
| 1979 | 47.5 mm (1.9 in) |
| 1980 | 35.3 mm (1.4 in) |
| 1981 | 34.6 mm (1.4 in) |
| 1982 | 51.3 mm (2.0 in) |
| 1983 | 49.3 mm (1.9 in) |
| 1984 | 64.8 mm (2.6 in) |
| 1985 | 55.3 mm (2.2 in) |
| 1986 | 42.1 mm (1.7 in) |
| 1987 | 44.1 mm (1.7 in) |
| 1988 | 45.3 mm (1.8 in) |
| 1989 | 58.1 mm (2.3 in) |
| 1990 | 46.3 mm (1.8 in) |
| 1991 | 23.1 mm (0.9 in) |
| 1992 | 45.7 mm (1.8 in) |
| 1993 | 30.0 mm (1.2 in) |
| 1994 | 26.9 mm (1.1 in) |
| 1995 | 50.3 mm (2.0 in) |
| 1996 | 43.2 mm (1.7 in) |
| 1997 | 33.8 mm (1.3 in) |
| 1998 | 66.9 mm (2.6 in) |
| 1999 | 30.4 mm (1.2 in) |
| 2000 | 53.8 mm (2.1 in) |
| 2001 | 51.2 mm (2.0 in) |
| 2002 | 55.3 mm (2.2 in) |
| 2003 | 60.8 mm (2.4 in) |
| 2004 | 25.8 mm (1.0 in) |
| 2005 | 38.6 mm (1.5 in) |
| 2006 | 89.4 mm (3.5 in) |
| 2007 | 52.8 mm (2.1 in) |
| 2008 | 103.4 mm (4.1 in) |
| 2009 | 33.4 mm (1.3 in) |
| 2010 | 45.0 mm (1.8 in) |
| 2011 | 40.2 mm (1.6 in) |
| 2012 | 28.8 mm (1.1 in) |
| 2013 | 25.6 mm (1.0 in) |
| 2014 | 72.1 mm (2.8 in) |
| 2015 | 35.1 mm (1.4 in) |
| 2016 | 35.8 mm (1.4 in) |
| 2017 | 34.4 mm (1.4 in) |
| 2018 | 41.1 mm (1.6 in) |
| 2019 | 44.0 mm (1.7 in) |
| 2020 | 93.1 mm (3.7 in) |
| 2021 | 32.8 mm (1.3 in) |
| 2022 | 26.5 mm (1.0 in) |
| 2023 | 33.1 mm (1.3 in) |
| 2024 | 32.0 mm (1.3 in) |
| 2025 | 34.3 mm (1.4 in) |
| 2026 | 51.4 mm (2.0 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1917 | n/a |
| 1919 | n/a |
| 1920 | n/a |
| 1937 | 32 days |
| 1940 | 21 days |
| 1941 | 39 days |
| 1942 | 32 days |
| 1943 | 55 days |
| 1944 | 67 days |
| 1945 | 49 days |
| 1946 | 62 days |
| 1947 | 108 days |
| 1948 | 35 days |
| 1949 | 39 days |
| 1950 | 37 days |
| 1951 | 44 days |
| 1952 | 51 days |
| 1953 | 52 days |
| 1954 | 48 days |
| 1955 | 30 days |
| 1956 | 83 days |
| 1957 | 70 days |
| 1958 | 66 days |
| 1959 | 41 days |
| 1960 | 33 days |
| 1961 | 56 days |
| 1962 | 52 days |
| 1963 | 46 days |
| 1964 | 50 days |
| 1965 | 45 days |
| 1966 | 43 days |
| 1967 | 23 days |
| 1968 | 79 days |
| 1969 | 61 days |
| 1970 | 43 days |
| 1971 | 35 days |
| 1972 | 44 days |
| 1973 | 66 days |
| 1974 | 72 days |
| 1975 | 34 days |
| 1976 | 66 days |
| 1977 | 45 days |
| 1978 | 68 days |
| 1979 | 67 days |
| 1980 | 109 days |
| 1981 | 40 days |
| 1982 | 34 days |
| 1983 | 49 days |
| 1984 | 109 days |
| 1985 | 39 days |
| 1986 | 26 days |
| 1987 | 43 days |
| 1988 | 24 days |
| 1989 | 40 days |
| 1990 | 8 days |
| 1991 | 5 days |
| 1992 | 5 days |
| 1993 | 17 days |
| 1994 | 25 days |
| 1995 | 54 days |
| 1996 | 49 days |
| 1997 | 29 days |
| 1998 | 86 days |
| 1999 | 69 days |
| 2000 | 73 days |
| 2001 | 80 days |
| 2002 | 59 days |
| 2003 | 69 days |
| 2004 | 44 days |
| 2005 | 83 days |
| 2006 | 80 days |
| 2007 | 40 days |
| 2008 | 53 days |
| 2009 | 56 days |
| 2010 | 42 days |
| 2011 | 37 days |
| 2012 | 42 days |
| 2013 | 58 days |
| 2014 | 86 days |
| 2015 | 40 days |
| 2016 | 42 days |
| 2017 | 47 days |
| 2018 | 38 days |
| 2019 | 49 days |
| 2020 | 37 days |
| 2021 | 37 days |
| 2022 | 48 days |
| 2023 | 28 days |
| 2024 | 42 days |
| 2025 | 26 days |
| 2026 | 31 days |
Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.
Frost Dates and Growing Season
80 years with a frostAcross 80 years with a frost, the median last spring frost at Big Delta AP falls on 18 May and the median first autumn frost on 2 September, which leaves a median of 106 days between them.
In 1994 to 2024 the median growing season was 105 days. That is 4 days fewer than in 1943 to 1972.
Fitted over all years, the growing season changes by +0.4 days per decade at this station.
| Measure | Median, all years | Earliest period (1943 to 1972) | Recent period (1994 to 2024) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 18 May | 18 May | 18 May | no change | 0.0 days per decade |
| First autumn frost | 2 September | 4 September | 3 September | 1 day earlier | +0.4 days per decade |
| Growing days | 106 days | 109 days | 105 days | 4 days fewer | +0.4 days per decade |
A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.
Rainfall Return Levels
78 years, 1941 to 2025A day with at least 25.1 mm (1.0 in) of rain is expected about once in 2 years. A day with at least 63.2 mm (2.5 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 25.1 mm (1.0 in) | |
| 5 years | 34.5 mm (1.4 in) | |
| 10 years | 41.0 mm (1.6 in) | |
| 25 years | 49.7 mm (2.0 in) | |
| 50 years | 56.3 mm (2.2 in) | |
| 100 years | 63.2 mm (2.5 in) | Longer than the 78 years of record |
The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 78 years of values from 1941 to 2025.
A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.
The largest wettest-day totals in the fit: 57.7 mm (2.3 in) in 2008; 54.4 mm (2.1 in) in 1943; 52.3 mm (2.1 in) in 1975.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Climate Twins
2009 to 2024 against 1961 to 1990Over 2009 to 2024, Big Delta AP had a mean temperature of -1.0 C (30.2 F) and 250.0 mm (9.8 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Bulgan (Mongolia, 6,112 km away), Tulun (Russia, 5,660 km away) and College Obsy (United States, 140 km away).
| Twin station | Country | Distance away | Mean temperature, 1961-1990 | Rain a year, 1961-1990 | Climate difference |
|---|---|---|---|---|---|
| Bulgan | Mongolia | 6,112 km (3,798 mi) | -0.6 C (30.8 F) | 306.4 mm (12.1 in) | 1.82 |
| Tulun | Russia | 5,660 km (3,517 mi) | -0.7 C (30.7 F) | 405.5 mm (16.0 in) | 1.90 |
| College Obsy | United States | 140 km (87 mi) | -2.5 C (27.5 F) | 309.9 mm (12.2 in) | 2.07 |
Twins are stations, not cities. A twin is one of the three stations at least 100 km away whose earlier climate is closest to this station's recent one, so a close match does not mean the two places look alike in other ways. A station move or a gap in a record can change that station's averages. The list describes past climate; it is not a forecast and does not say what caused any change. How twins are found, and a search for any station.
Download the Data
Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-15 (15 October 2026). Records are computed by this site and are not official.
Data as of . Last revised (2026-10-15).