Boulder Weather Records (USC00420849)
Record envelope, standing records and threshold days for Boulder (USC00420849), Utah, United States, with 73 years of record.
Key Facts for Boulder
- Boulder (USC00420849) is a weather station in Utah, United States at 37.91 latitude and -111.42 longitude, 2,027 m (6,650 ft) above sea level.
- The station reports from 1954 to 2026, 73 years of record.
- 1,464 records set at Boulder still stand.
- Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
- Boulder set a daily record precipitation of 21.1 mm (0.8 in) on 31 August 2026 (provisional).
Provisional Records
Records set in the last 60 days are provisional until they clear the revision window.
About the Station
- Location: Utah, United States, 37.91 latitude, -111.42 longitude.
- Elevation: 2,027 m (6,650 ft).
- Period of record: 1954 to 2026, 73 years.
- Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
24 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 17.2 C (63.0 F) | -26.7 C (-16.1 F) | 13.3 C (55.9 F) | -10.0 C (14.0 F) |
| Feb | 20.6 C (69.1 F) | -27.2 C (-17.0 F) | 19.4 C (66.9 F) | -13.9 C (7.0 F) |
| Mar | 27.8 C (82.0 F) | -17.8 C (0.0 F) | 27.8 C (82.0 F) | -5.6 C (21.9 F) |
| Apr | 27.8 C (82.0 F) | -13.3 C (8.1 F) | 22.8 C (73.0 F) | -4.4 C (24.1 F) |
| May | 31.7 C (89.1 F) | -6.7 C (19.9 F) | 28.3 C (82.9 F) | 0.6 C (33.1 F) |
| Jun | 36.1 C (97.0 F) | -2.8 C (27.0 F) | 33.3 C (91.9 F) | 6.1 C (43.0 F) |
| Jul | 35.6 C (96.1 F) | 0.0 C (32.0 F) | 33.3 C (91.9 F) | 12.2 C (54.0 F) |
| Aug | 35.0 C (95.0 F) | 1.1 C (34.0 F) | 33.9 C (93.0 F) | 10.0 C (50.0 F) |
| Sep | 33.9 C (93.0 F) | -4.4 C (24.1 F) | 30.0 C (86.0 F) | 7.8 C (46.0 F) |
| Oct | 29.4 C (84.9 F) | -15.6 C (3.9 F) | 24.4 C (75.9 F) | 11.7 C (53.1 F) |
| Nov | 21.7 C (71.1 F) | -18.3 C (-0.9 F) | n/a | n/a |
| Dec | 18.3 C (64.9 F) | -23.9 C (-11.0 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1954 | 6 |
| 1955 | 35 |
| 1956 | 28 |
| 1957 | 13 |
| 1958 | 21 |
| 1959 | 18 |
| 1960 | 27 |
| 1961 | 19 |
| 1962 | 41 |
| 1963 | 25 |
| 1964 | 28 |
| 1965 | 22 |
| 1966 | 33 |
| 1967 | 20 |
| 1968 | 28 |
| 1969 | 17 |
| 1970 | 23 |
| 1971 | 36 |
| 1972 | 21 |
| 1973 | 15 |
| 1974 | 13 |
| 1975 | 35 |
| 1976 | 12 |
| 1977 | 14 |
| 1978 | 13 |
| 1979 | 29 |
| 1980 | 30 |
| 1981 | 16 |
| 1982 | 15 |
| 1983 | 8 |
| 1984 | 18 |
| 1985 | 15 |
| 1986 | 24 |
| 1987 | 19 |
| 1988 | 18 |
| 1989 | 35 |
| 1990 | 24 |
| 1991 | 14 |
| 1992 | 12 |
| 1993 | 5 |
| 1994 | 14 |
| 1995 | 36 |
| 1996 | 48 |
| 1997 | 9 |
| 1998 | 13 |
| 1999 | 17 |
| 2000 | 36 |
| 2001 | 13 |
| 2002 | 19 |
| 2003 | 23 |
| 2004 | 5 |
| 2005 | 3 |
| 2006 | 12 |
| 2007 | 14 |
| 2008 | 17 |
| 2009 | 9 |
| 2010 | 15 |
| 2011 | 11 |
| 2012 | 12 |
| 2013 | 19 |
| 2014 | 11 |
| 2015 | 20 |
| 2016 | 10 |
| 2017 | 33 |
| 2018 | 16 |
| 2019 | 15 |
| 2020 | 32 |
| 2021 | 25 |
| 2022 | 16 |
| 2023 | 15 |
| 2024 | 19 |
| 2025 | 25 |
| 2026 | 37 |
All-Time Record Progression
16 new records| Date | Kind | Detail |
|---|---|---|
| 1989-02-06 | Record low minimum temperature | Record low minimum temperature -27.2 C (-17.0 F) |
| 1992-01-06 | Record daily snowfall | Record daily snowfall 40.6 cm (16.0 in) |
| 1993-01-19 | Record snow depth | Record snow depth 68.6 cm (27.0 in) |
| 1993-02-09 | Record snow depth | Record snow depth 78.7 cm (31.0 in) |
| 1993-02-20 | Record snow depth | Record snow depth 83.8 cm (33.0 in) |
| 1993-02-21 | Record snow depth | Record snow depth 86.4 cm (34.0 in) |
| 1997-01-13 | Record daily snowfall | Record daily snowfall 45.7 cm (18.0 in) |
| 2003-07-12 | Record high minimum temperature | Record high minimum temperature 22.8 C (73.0 F) |
| 2006-10-06 | Record daily precipitation | Record daily precipitation 73.2 mm (2.9 in) |
| 2010-01-22 | Record daily snowfall | Record daily snowfall 50.8 cm (20.0 in) |
| 2010-01-27 | Record snow depth | Record snow depth 91.4 cm (36.0 in) |
| 2010-01-28 | Record snow depth | Record snow depth 96.5 cm (38.0 in) |
| 2018-07-22 | Record high minimum temperature | Record high minimum temperature 23.3 C (73.9 F) |
| 2021-06-16 | Record high maximum temperature | Record high maximum temperature 36.1 C (97.0 F) |
| 2021-06-17 | Record high minimum temperature | Record high minimum temperature 23.9 C (75.0 F) |
| 2021-07-09 | Record high minimum temperature | Record high minimum temperature 25.6 C (78.1 F) |
Wettest Day of Each Month
Oct: 73.2 mm (2.9 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 38.4 mm (1.5 in) | 13 January 1997 |
| Feb | 30.7 mm (1.2 in) | 14 February 1980 |
| Mar | 33.3 mm (1.3 in) | 4 March 1969 |
| Apr | 38.1 mm (1.5 in) | 3 April 1964 |
| May | 30.5 mm (1.2 in) | 15 May 2003 |
| Jun | 41.9 mm (1.6 in) | 29 June 1956 |
| Jul | 59.2 mm (2.3 in) | 20 July 1969 |
| Aug | 41.1 mm (1.6 in) | 13 August 2009 |
| Sep | 55.9 mm (2.2 in) | 23 September 2016 |
| Oct | 73.2 mm (2.9 in) | 6 October 2006 |
| Nov | 47.0 mm (1.9 in) | 11 November 1978 |
| Dec | 31.8 mm (1.3 in) | 26 December 2003 |
Period of Record Coverage
1954 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1954 | 202 | 55% | No |
| 1955 | 362 | 99% | Yes |
| 1956 | 358 | 98% | Yes |
| 1957 | 360 | 99% | Yes |
| 1958 | 358 | 98% | Yes |
| 1959 | 358 | 98% | Yes |
| 1960 | 362 | 99% | Yes |
| 1961 | 355 | 97% | Yes |
| 1962 | 362 | 99% | Yes |
| 1963 | 362 | 99% | Yes |
| 1964 | 365 | 100% | Yes |
| 1965 | 365 | 100% | Yes |
| 1966 | 362 | 99% | Yes |
| 1967 | 364 | 100% | Yes |
| 1968 | 366 | 100% | Yes |
| 1969 | 365 | 100% | Yes |
| 1970 | 364 | 100% | Yes |
| 1971 | 365 | 100% | Yes |
| 1972 | 366 | 100% | Yes |
| 1973 | 365 | 100% | Yes |
| 1974 | 364 | 100% | Yes |
| 1975 | 364 | 100% | Yes |
| 1976 | 366 | 100% | Yes |
| 1977 | 364 | 100% | Yes |
| 1978 | 365 | 100% | Yes |
| 1979 | 364 | 100% | Yes |
| 1980 | 364 | 99% | Yes |
| 1981 | 363 | 99% | Yes |
| 1982 | 359 | 98% | Yes |
| 1983 | 360 | 99% | Yes |
| 1984 | 358 | 98% | Yes |
| 1985 | 360 | 99% | Yes |
| 1986 | 359 | 98% | Yes |
| 1987 | 360 | 99% | Yes |
| 1988 | 358 | 98% | Yes |
| 1989 | 353 | 97% | Yes |
| 1990 | 348 | 95% | Yes |
| 1991 | 351 | 96% | Yes |
| 1992 | 355 | 97% | Yes |
| 1993 | 347 | 95% | Yes |
| 1994 | 358 | 98% | Yes |
| 1995 | 356 | 98% | Yes |
| 1996 | 356 | 97% | Yes |
| 1997 | 362 | 99% | Yes |
| 1998 | 362 | 99% | Yes |
| 1999 | 361 | 99% | Yes |
| 2000 | 360 | 98% | Yes |
| 2001 | 362 | 99% | Yes |
| 2002 | 363 | 99% | Yes |
| 2003 | 357 | 98% | Yes |
| 2004 | 348 | 95% | Yes |
| 2005 | 354 | 97% | Yes |
| 2006 | 334 | 92% | Yes |
| 2007 | 358 | 98% | Yes |
| 2008 | 357 | 98% | Yes |
| 2009 | 363 | 99% | Yes |
| 2010 | 363 | 99% | Yes |
| 2011 | 365 | 100% | Yes |
| 2012 | 364 | 99% | Yes |
| 2013 | 365 | 100% | Yes |
| 2014 | 365 | 100% | Yes |
| 2015 | 364 | 100% | Yes |
| 2016 | 363 | 99% | Yes |
| 2017 | 365 | 100% | Yes |
| 2018 | 365 | 100% | Yes |
| 2019 | 365 | 100% | Yes |
| 2020 | 366 | 100% | Yes |
| 2021 | 365 | 100% | Yes |
| 2022 | 360 | 99% | Yes |
| 2023 | 365 | 100% | Yes |
| 2024 | 341 | 93% | Yes |
| 2025 | 364 | 100% | Yes |
| 2026 | 260 | 71% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 31 August 2026 | Boulder, US | daily rain (Provisional) | 21.1 mm (0.8 in) | 2.8 mm (0.11 in) | 60 years | 20 of 100 (Routine) |
| 8 August 2026 | Boulder, US | daily high min | 22.2 C (72.0 F) | 2.2 C (4.0 F) | 13 years | 18 of 100 (Routine) |
| 7 August 2026 | Boulder, US | daily high min | 20.0 C (68.0 F) | 1.1 C (2.0 F) | 28 years | 18 of 100 (Routine) |
| 7 August 2026 | Boulder, US | daily high max (Tie) | 33.3 C (91.9 F) | tie | 48 years | 5 of 100 (Routine) |
| 5 August 2026 | Boulder, US | daily high max | 33.9 C (93.0 F) | 0.6 C (1.1 F) | 47 years | 23 of 100 (Routine) |
| 4 August 2026 | Boulder, US | daily high max (Tie) | 33.9 C (93.0 F) | tie | 47 years | 5 of 100 (Routine) |
| 1 August 2026 | Boulder, US | daily high min | 22.2 C (72.0 F) | 0.5 C (0.9 F) | 8 years | 10 of 100 (Routine) |
| 25 July 2026 | Boulder, US | daily high max | 33.3 C (91.9 F) | 0.5 C (0.9 F) | 65 years | 27 of 100 (Routine) |
| 29 June 2026 | Boulder, US | daily low min | 6.1 C (43.0 F) | 2.2 C (4.0 F) | 56 years | 29 of 100 (Routine) |
| 17 June 2026 | Boulder, US | daily high max (Tie) | 33.3 C (91.9 F) | tie | 4 years | 2 of 100 (Routine) |
| 4 June 2026 | Boulder, US | daily high min | 18.3 C (64.9 F) | 2.2 C (4.0 F) | 8 years | 14 of 100 (Routine) |
| 13 May 2026 | Boulder, US | daily high min | 14.4 C (57.9 F) | 0.5 C (0.9 F) | 52 years | 23 of 100 (Routine) |
| 12 May 2026 | Boulder, US | daily high min | 12.8 C (55.0 F) | 0.6 C (1.1 F) | 19 years | 13 of 100 (Routine) |
| 26 April 2026 | Boulder, US | daily snowfall (Tie) | 1.3 cm (0.5 in) | tie | 32 years | 4 of 100 (Routine) |
| 29 March 2026 | Boulder, US | daily high max (Tie) | 22.2 C (72.0 F) | tie | 11 years | 2 of 100 (Routine) |
| 27 March 2026 | Boulder, US | daily high max | 23.3 C (73.9 F) | 1.6 C (2.9 F) | 4 years | 11 of 100 (Routine) |
| 26 March 2026 | Boulder, US | daily high max | 26.1 C (79.0 F) | 2.8 C (5.0 F) | 4 years | 13 of 100 (Routine) |
| 26 March 2026 | Boulder, US | daily high min | 8.3 C (46.9 F) | 0.5 C (0.9 F) | 0 years | 8 of 100 (Routine) |
| 25 March 2026 | Boulder, US | monthly high min | 13.9 C (57.0 F) | 1.1 C (2.0 F) | 0 years | 19 of 100 (Routine) |
| 25 March 2026 | Boulder, US | daily high max | 26.7 C (80.1 F) | 4.5 C (8.1 F) | 4 years | 17 of 100 (Routine) |
Climate Trend
67 complete years, 1955 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1955 | 8.4 C | -1.35 C |
| 1956 | 9.8 C | +0.05 C |
| 1957 | 8.6 C | -1.10 C |
| 1958 | 9.8 C | +0.10 C |
| 1959 | 9.3 C | -0.45 C |
| 1960 | 9.1 C | -0.65 C |
| 1961 | 9.0 C | -0.74 C |
| 1962 | 9.6 C | -0.13 C |
| 1963 | 9.5 C | -0.16 C |
| 1964 | 8.5 C | -1.25 C |
| 1965 | 8.8 C | -0.90 C |
| 1966 | 9.5 C | -0.19 C |
| 1967 | 9.1 C | -0.62 C |
| 1968 | 8.6 C | -1.15 C |
| 1969 | 9.1 C | -0.57 C |
| 1970 | 8.9 C | -0.79 C |
| 1971 | 8.4 C | -1.31 C |
| 1972 | 9.6 C | -0.12 C |
| 1973 | 8.5 C | -1.18 C |
| 1974 | 9.1 C | -0.56 C |
| 1975 | 8.1 C | -1.59 C |
| 1976 | 9.4 C | -0.29 C |
| 1977 | 10.0 C | +0.25 C |
| 1978 | 9.1 C | -0.60 C |
| 1979 | 8.7 C | -0.97 C |
| 1980 | 9.7 C | 0.00 C |
| 1981 | 10.3 C | +0.55 C |
| 1982 | 8.3 C | -1.36 C |
| 1984 | 9.0 C | -0.72 C |
| 1985 | 9.2 C | -0.46 C |
| 1986 | 9.9 C | +0.21 C |
| 1987 | 9.3 C | -0.37 C |
| 1988 | 9.9 C | +0.16 C |
| 1989 | 10.2 C | +0.46 C |
| 1990 | 9.9 C | +0.21 C |
| 1991 | 9.2 C | -0.48 C |
| 1992 | 9.6 C | -0.12 C |
| 1994 | 10.5 C | +0.82 C |
| 1995 | 10.6 C | +0.93 C |
| 1996 | 11.1 C | +1.40 C |
| 1997 | 10.0 C | +0.26 C |
| 1998 | 9.5 C | -0.20 C |
| 1999 | 10.5 C | +0.80 C |
| 2000 | 10.3 C | +0.58 C |
| 2001 | 10.2 C | +0.45 C |
| 2002 | 10.3 C | +0.64 C |
| 2003 | 10.9 C | +1.18 C |
| 2004 | 9.7 C | -0.04 C |
| 2005 | 10.0 C | +0.33 C |
| 2007 | 10.4 C | +0.74 C |
| 2008 | 9.5 C | -0.21 C |
| 2009 | 9.6 C | -0.07 C |
| 2010 | 9.1 C | -0.60 C |
| 2011 | 9.3 C | -0.38 C |
| 2012 | 11.0 C | +1.27 C |
| 2013 | 9.5 C | -0.24 C |
| 2014 | 10.8 C | +1.12 C |
| 2015 | 10.5 C | +0.81 C |
| 2016 | 10.5 C | +0.83 C |
| 2017 | 11.4 C | +1.74 C |
| 2018 | 11.0 C | +1.28 C |
| 2019 | 9.4 C | -0.26 C |
| 2020 | 11.1 C | +1.38 C |
| 2021 | 10.9 C | +1.21 C |
| 2022 | 10.6 C | +0.85 C |
| 2023 | 9.6 C | -0.06 C |
| 2025 | 11.6 C | +1.91 C |
The annual mean temperature here has risen by 0.3 C (0.2 to 0.3) per decade over 1955 to 2025. In Fahrenheit: 0.5 F (0.4 to 0.6) per decade. The slope is a straight line fitted to 67 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 (0.2 to 0.3) per decade | 0.5 F (0.4 to 0.6) per decade | 1955 to 2025 | 67 | Rise |
| Mean daily maximum | 0.09 C (0.00 to 0.19) per decade | 0.17 F (-0.01 to 0.34) per decade | 1955 to 2025 | 67 | Not clearly different from zero |
| Mean daily minimum | 0.4 C (0.4 to 0.5) per decade | 0.8 F (0.7 to 0.9) per decade | 1955 to 2025 | 67 | 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
1954 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 36.1 C (97.0 F) | 2021 | 33.9 C (93.0 F) | 73 |
| Coldest night (TNn) | -27.2 C (-17.0 F) | 1989 | -17.2 C (1.0 F) | 73 |
| Wettest day (Rx1day) | 73.2 mm (2.9 in) | 2006 | 26.7 mm (1.1 in) | 73 |
| Wettest five days (Rx5day) | 110.0 mm (4.3 in) | 1969 | 42.7 mm (1.7 in) | 73 |
| Longest dry spell (CDD) | 103 days | 1972 | 45 days | 73 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1954 | 34.4 C (93.9 F) |
| 1955 | 32.8 C (91.0 F) |
| 1956 | 33.3 C (91.9 F) |
| 1957 | 33.3 C (91.9 F) |
| 1958 | 33.9 C (93.0 F) |
| 1959 | 33.3 C (91.9 F) |
| 1960 | 34.4 C (93.9 F) |
| 1961 | 35.6 C (96.1 F) |
| 1962 | 35.0 C (95.0 F) |
| 1963 | 33.3 C (91.9 F) |
| 1964 | 33.9 C (93.0 F) |
| 1965 | 31.7 C (89.1 F) |
| 1966 | 33.3 C (91.9 F) |
| 1967 | 33.3 C (91.9 F) |
| 1968 | 33.3 C (91.9 F) |
| 1969 | 34.4 C (93.9 F) |
| 1970 | 35.0 C (95.0 F) |
| 1971 | 35.0 C (95.0 F) |
| 1972 | 35.0 C (95.0 F) |
| 1973 | 35.0 C (95.0 F) |
| 1974 | 35.0 C (95.0 F) |
| 1975 | 32.2 C (90.0 F) |
| 1976 | 35.0 C (95.0 F) |
| 1977 | 33.9 C (93.0 F) |
| 1978 | 33.9 C (93.0 F) |
| 1979 | 34.4 C (93.9 F) |
| 1980 | 34.4 C (93.9 F) |
| 1981 | 34.4 C (93.9 F) |
| 1982 | 32.8 C (91.0 F) |
| 1983 | 31.7 C (89.1 F) |
| 1984 | 33.3 C (91.9 F) |
| 1985 | 35.0 C (95.0 F) |
| 1986 | 33.9 C (93.0 F) |
| 1987 | 31.1 C (88.0 F) |
| 1988 | 33.9 C (93.0 F) |
| 1989 | 35.6 C (96.1 F) |
| 1990 | 33.9 C (93.0 F) |
| 1991 | 33.3 C (91.9 F) |
| 1992 | 33.3 C (91.9 F) |
| 1993 | 33.3 C (91.9 F) |
| 1994 | 34.4 C (93.9 F) |
| 1995 | 34.4 C (93.9 F) |
| 1996 | 34.4 C (93.9 F) |
| 1997 | 32.8 C (91.0 F) |
| 1998 | 34.4 C (93.9 F) |
| 1999 | 33.9 C (93.0 F) |
| 2000 | 34.4 C (93.9 F) |
| 2001 | 33.9 C (93.0 F) |
| 2002 | 35.6 C (96.1 F) |
| 2003 | 35.0 C (95.0 F) |
| 2004 | 31.7 C (89.1 F) |
| 2005 | 33.9 C (93.0 F) |
| 2006 | 32.8 C (91.0 F) |
| 2007 | 32.8 C (91.0 F) |
| 2008 | 31.1 C (88.0 F) |
| 2009 | 33.3 C (91.9 F) |
| 2010 | 32.8 C (91.0 F) |
| 2011 | 32.2 C (90.0 F) |
| 2012 | 31.7 C (89.1 F) |
| 2013 | 35.0 C (95.0 F) |
| 2014 | 32.8 C (91.0 F) |
| 2015 | 33.3 C (91.9 F) |
| 2016 | 33.9 C (93.0 F) |
| 2017 | 33.3 C (91.9 F) |
| 2018 | 32.8 C (91.0 F) |
| 2019 | 31.7 C (89.1 F) |
| 2020 | 33.9 C (93.0 F) |
| 2021 | 36.1 C (97.0 F) |
| 2022 | 32.8 C (91.0 F) |
| 2023 | 35.0 C (95.0 F) |
| 2024 | 33.3 C (91.9 F) |
| 2025 | 33.3 C (91.9 F) |
| 2026 | 33.9 C (93.0 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1954 | -17.8 C (0.0 F) |
| 1955 | -20.6 C (-5.1 F) |
| 1956 | -17.2 C (1.0 F) |
| 1957 | -19.4 C (-2.9 F) |
| 1958 | -14.4 C (6.1 F) |
| 1959 | -18.9 C (-2.0 F) |
| 1960 | -22.2 C (-8.0 F) |
| 1961 | -20.6 C (-5.1 F) |
| 1962 | -20.0 C (-4.0 F) |
| 1963 | -26.7 C (-16.1 F) |
| 1964 | -18.3 C (-0.9 F) |
| 1965 | -16.1 C (3.0 F) |
| 1966 | -19.4 C (-2.9 F) |
| 1967 | -18.9 C (-2.0 F) |
| 1968 | -19.4 C (-2.9 F) |
| 1969 | -17.2 C (1.0 F) |
| 1970 | -18.3 C (-0.9 F) |
| 1971 | -26.1 C (-15.0 F) |
| 1972 | -19.4 C (-2.9 F) |
| 1973 | -21.7 C (-7.1 F) |
| 1974 | -21.7 C (-7.1 F) |
| 1975 | -16.7 C (1.9 F) |
| 1976 | -18.9 C (-2.0 F) |
| 1977 | -17.2 C (1.0 F) |
| 1978 | -23.9 C (-11.0 F) |
| 1979 | -22.8 C (-9.0 F) |
| 1980 | -13.9 C (7.0 F) |
| 1981 | -12.8 C (9.0 F) |
| 1982 | -22.2 C (-8.0 F) |
| 1983 | -16.7 C (1.9 F) |
| 1984 | -20.6 C (-5.1 F) |
| 1985 | -24.4 C (-11.9 F) |
| 1986 | -16.1 C (3.0 F) |
| 1987 | -17.8 C (0.0 F) |
| 1988 | -20.0 C (-4.0 F) |
| 1989 | -27.2 C (-17.0 F) |
| 1990 | -23.9 C (-11.0 F) |
| 1991 | -15.6 C (3.9 F) |
| 1992 | -17.8 C (0.0 F) |
| 1993 | -18.9 C (-2.0 F) |
| 1994 | -15.6 C (3.9 F) |
| 1995 | -11.7 C (10.9 F) |
| 1996 | -16.7 C (1.9 F) |
| 1997 | -15.6 C (3.9 F) |
| 1998 | -16.1 C (3.0 F) |
| 1999 | -13.3 C (8.1 F) |
| 2000 | -13.3 C (8.1 F) |
| 2001 | -15.6 C (3.9 F) |
| 2002 | -16.7 C (1.9 F) |
| 2003 | -13.9 C (7.0 F) |
| 2004 | -16.7 C (1.9 F) |
| 2005 | -15.6 C (3.9 F) |
| 2006 | -15.6 C (3.9 F) |
| 2007 | -17.2 C (1.0 F) |
| 2008 | -21.1 C (-6.0 F) |
| 2009 | -18.3 C (-0.9 F) |
| 2010 | -15.0 C (5.0 F) |
| 2011 | -20.0 C (-4.0 F) |
| 2012 | -15.0 C (5.0 F) |
| 2013 | -21.7 C (-7.1 F) |
| 2014 | -12.2 C (10.0 F) |
| 2015 | -15.0 C (5.0 F) |
| 2016 | -16.7 C (1.9 F) |
| 2017 | -17.2 C (1.0 F) |
| 2018 | -13.9 C (7.0 F) |
| 2019 | -16.1 C (3.0 F) |
| 2020 | -14.4 C (6.1 F) |
| 2021 | -12.8 C (9.0 F) |
| 2022 | -15.0 C (5.0 F) |
| 2023 | -15.0 C (5.0 F) |
| 2024 | -12.2 C (10.0 F) |
| 2025 | -15.6 C (3.9 F) |
| 2026 | -13.9 C (7.0 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1954 | 17.3 mm (0.7 in) |
| 1955 | 22.9 mm (0.9 in) |
| 1956 | 41.9 mm (1.6 in) |
| 1957 | 36.6 mm (1.4 in) |
| 1958 | 21.6 mm (0.9 in) |
| 1959 | 25.7 mm (1.0 in) |
| 1960 | 50.8 mm (2.0 in) |
| 1961 | 18.8 mm (0.7 in) |
| 1962 | 48.8 mm (1.9 in) |
| 1963 | 26.9 mm (1.1 in) |
| 1964 | 38.1 mm (1.5 in) |
| 1965 | 31.0 mm (1.2 in) |
| 1966 | 18.3 mm (0.7 in) |
| 1967 | 22.1 mm (0.9 in) |
| 1968 | 16.5 mm (0.6 in) |
| 1969 | 59.2 mm (2.3 in) |
| 1970 | 34.8 mm (1.4 in) |
| 1971 | 24.9 mm (1.0 in) |
| 1972 | 41.7 mm (1.6 in) |
| 1973 | 25.4 mm (1.0 in) |
| 1974 | 20.6 mm (0.8 in) |
| 1975 | 19.1 mm (0.8 in) |
| 1976 | 33.8 mm (1.3 in) |
| 1977 | 13.5 mm (0.5 in) |
| 1978 | 47.0 mm (1.9 in) |
| 1979 | 21.3 mm (0.8 in) |
| 1980 | 30.7 mm (1.2 in) |
| 1981 | 36.1 mm (1.4 in) |
| 1982 | 38.1 mm (1.5 in) |
| 1983 | 35.8 mm (1.4 in) |
| 1984 | 24.4 mm (1.0 in) |
| 1985 | 23.6 mm (0.9 in) |
| 1986 | 23.6 mm (0.9 in) |
| 1987 | 18.5 mm (0.7 in) |
| 1988 | 17.8 mm (0.7 in) |
| 1989 | 14.5 mm (0.6 in) |
| 1990 | 26.4 mm (1.0 in) |
| 1991 | 41.9 mm (1.6 in) |
| 1992 | 25.7 mm (1.0 in) |
| 1993 | 26.7 mm (1.1 in) |
| 1994 | 21.1 mm (0.8 in) |
| 1995 | 20.3 mm (0.8 in) |
| 1996 | 16.0 mm (0.6 in) |
| 1997 | 38.4 mm (1.5 in) |
| 1998 | 34.5 mm (1.4 in) |
| 1999 | 39.4 mm (1.6 in) |
| 2000 | 19.6 mm (0.8 in) |
| 2001 | 23.1 mm (0.9 in) |
| 2002 | 24.1 mm (0.9 in) |
| 2003 | 31.8 mm (1.3 in) |
| 2004 | 33.8 mm (1.3 in) |
| 2005 | 33.0 mm (1.3 in) |
| 2006 | 73.2 mm (2.9 in) |
| 2007 | 21.1 mm (0.8 in) |
| 2008 | 16.5 mm (0.6 in) |
| 2009 | 41.1 mm (1.6 in) |
| 2010 | 43.2 mm (1.7 in) |
| 2011 | 26.9 mm (1.1 in) |
| 2012 | 29.5 mm (1.2 in) |
| 2013 | 47.8 mm (1.9 in) |
| 2014 | 21.1 mm (0.8 in) |
| 2015 | 31.0 mm (1.2 in) |
| 2016 | 55.9 mm (2.2 in) |
| 2017 | 31.0 mm (1.2 in) |
| 2018 | 20.1 mm (0.8 in) |
| 2019 | 27.9 mm (1.1 in) |
| 2020 | 18.8 mm (0.7 in) |
| 2021 | 43.7 mm (1.7 in) |
| 2022 | 24.6 mm (1.0 in) |
| 2023 | 33.0 mm (1.3 in) |
| 2024 | 20.1 mm (0.8 in) |
| 2025 | 47.0 mm (1.9 in) |
| 2026 | 21.1 mm (0.8 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1954 | 33.8 mm (1.3 in) |
| 1955 | 26.7 mm (1.1 in) |
| 1956 | 48.8 mm (1.9 in) |
| 1957 | 77.1 mm (3.0 in) |
| 1958 | 27.9 mm (1.1 in) |
| 1959 | 41.4 mm (1.6 in) |
| 1960 | 71.9 mm (2.8 in) |
| 1961 | 34.2 mm (1.3 in) |
| 1962 | 69.3 mm (2.7 in) |
| 1963 | 47.0 mm (1.9 in) |
| 1964 | 47.0 mm (1.9 in) |
| 1965 | 41.9 mm (1.6 in) |
| 1966 | 30.0 mm (1.2 in) |
| 1967 | 42.7 mm (1.7 in) |
| 1968 | 41.8 mm (1.6 in) |
| 1969 | 110.0 mm (4.3 in) |
| 1970 | 38.9 mm (1.5 in) |
| 1971 | 34.8 mm (1.4 in) |
| 1972 | 86.7 mm (3.4 in) |
| 1973 | 28.0 mm (1.1 in) |
| 1974 | 36.1 mm (1.4 in) |
| 1975 | 30.0 mm (1.2 in) |
| 1976 | 47.3 mm (1.9 in) |
| 1977 | 23.9 mm (0.9 in) |
| 1978 | 66.8 mm (2.6 in) |
| 1979 | 35.1 mm (1.4 in) |
| 1980 | 60.5 mm (2.4 in) |
| 1981 | 47.3 mm (1.9 in) |
| 1982 | 49.5 mm (1.9 in) |
| 1983 | 49.6 mm (2.0 in) |
| 1984 | 24.4 mm (1.0 in) |
| 1985 | 47.5 mm (1.9 in) |
| 1986 | 43.6 mm (1.7 in) |
| 1987 | 45.0 mm (1.8 in) |
| 1988 | 35.0 mm (1.4 in) |
| 1989 | 26.7 mm (1.1 in) |
| 1990 | 35.8 mm (1.4 in) |
| 1991 | 45.7 mm (1.8 in) |
| 1992 | 33.3 mm (1.3 in) |
| 1993 | 58.2 mm (2.3 in) |
| 1994 | 35.8 mm (1.4 in) |
| 1995 | 25.9 mm (1.0 in) |
| 1996 | 27.2 mm (1.1 in) |
| 1997 | 54.4 mm (2.1 in) |
| 1998 | 55.6 mm (2.2 in) |
| 1999 | 40.7 mm (1.6 in) |
| 2000 | 37.1 mm (1.5 in) |
| 2001 | 36.9 mm (1.5 in) |
| 2002 | 40.1 mm (1.6 in) |
| 2003 | 35.4 mm (1.4 in) |
| 2004 | 62.8 mm (2.5 in) |
| 2005 | 56.9 mm (2.2 in) |
| 2006 | 107.7 mm (4.2 in) |
| 2007 | 31.5 mm (1.2 in) |
| 2008 | 30.9 mm (1.2 in) |
| 2009 | 42.4 mm (1.7 in) |
| 2010 | 95.0 mm (3.7 in) |
| 2011 | 50.8 mm (2.0 in) |
| 2012 | 33.0 mm (1.3 in) |
| 2013 | 87.4 mm (3.4 in) |
| 2014 | 35.3 mm (1.4 in) |
| 2015 | 50.6 mm (2.0 in) |
| 2016 | 73.4 mm (2.9 in) |
| 2017 | 54.9 mm (2.2 in) |
| 2018 | 47.3 mm (1.9 in) |
| 2019 | 44.0 mm (1.7 in) |
| 2020 | 30.7 mm (1.2 in) |
| 2021 | 58.2 mm (2.3 in) |
| 2022 | 57.8 mm (2.3 in) |
| 2023 | 58.4 mm (2.3 in) |
| 2024 | 31.0 mm (1.2 in) |
| 2025 | 67.3 mm (2.6 in) |
| 2026 | 28.8 mm (1.1 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1954 | 34 days |
| 1955 | 85 days |
| 1956 | 77 days |
| 1957 | 33 days |
| 1958 | 49 days |
| 1959 | 67 days |
| 1960 | 31 days |
| 1961 | 34 days |
| 1962 | 33 days |
| 1963 | 40 days |
| 1964 | 50 days |
| 1965 | 28 days |
| 1966 | 43 days |
| 1967 | 56 days |
| 1968 | 41 days |
| 1969 | 61 days |
| 1970 | 44 days |
| 1971 | 62 days |
| 1972 | 103 days |
| 1973 | 68 days |
| 1974 | 86 days |
| 1975 | 38 days |
| 1976 | 47 days |
| 1977 | 103 days |
| 1978 | 35 days |
| 1979 | 47 days |
| 1980 | 52 days |
| 1981 | 28 days |
| 1982 | 45 days |
| 1983 | 39 days |
| 1984 | 62 days |
| 1985 | 26 days |
| 1986 | 40 days |
| 1987 | 21 days |
| 1988 | 52 days |
| 1989 | 70 days |
| 1990 | 31 days |
| 1991 | 63 days |
| 1992 | 34 days |
| 1993 | 38 days |
| 1994 | 75 days |
| 1995 | 35 days |
| 1996 | 56 days |
| 1997 | 38 days |
| 1998 | 33 days |
| 1999 | 76 days |
| 2000 | 32 days |
| 2001 | 37 days |
| 2002 | 52 days |
| 2003 | 69 days |
| 2004 | 28 days |
| 2005 | 34 days |
| 2006 | 45 days |
| 2007 | 37 days |
| 2008 | 66 days |
| 2009 | 75 days |
| 2010 | 37 days |
| 2011 | 49 days |
| 2012 | 69 days |
| 2013 | 57 days |
| 2014 | 45 days |
| 2015 | 44 days |
| 2016 | 73 days |
| 2017 | 94 days |
| 2018 | 45 days |
| 2019 | 70 days |
| 2020 | 39 days |
| 2021 | 50 days |
| 2022 | 81 days |
| 2023 | 45 days |
| 2024 | 36 days |
| 2025 | 49 days |
| 2026 | 53 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
67 years with a frostAcross 67 years with a frost, the median last spring frost at Boulder falls on 15 May and the median first autumn frost on 4 October, which leaves a median of 142 days between them.
In 1994 to 2025 the median growing season was 147 days. That is 8 days more than in 1955 to 1985.
Fitted over all years, the growing season changes by +3.2 days per decade at this station.
| Measure | Median, all years | Earliest period (1955 to 1985) | Recent period (1994 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 15 May | 18 May | 12 May | 6 days earlier | -1.5 days per decade |
| First autumn frost | 4 October | 29 September | 6 October | 7 days later | +1.7 days per decade |
| Growing days | 142 days | 139 days | 147 days | 8 days more | +3.2 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
70 years, 1955 to 2025A day with at least 27.8 mm (1.1 in) of rain is expected about once in 2 years. A day with at least 72.1 mm (2.8 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 27.8 mm (1.1 in) | |
| 5 years | 38.3 mm (1.5 in) | |
| 10 years | 45.8 mm (1.8 in) | |
| 25 years | 55.8 mm (2.2 in) | |
| 50 years | 63.8 mm (2.5 in) | |
| 100 years | 72.1 mm (2.8 in) | Longer than the 70 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, 70 years of values from 1955 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: 73.2 mm (2.9 in) in 2006; 59.2 mm (2.3 in) in 1969; 55.9 mm (2.2 in) in 2016.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Climate Twins
2010 to 2025 against 1961 to 1990Over 2010 to 2025, Boulder had a mean temperature of 10.4 C (50.8 F) and 316.6 mm (12.5 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Cedar City AP (United States, 149 km away), Pedernal 9 E (United States, 646 km away) and Keams Canyon (United States, 257 km away).
| Twin station | Country | Distance away | Mean temperature, 1961-1990 | Rain a year, 1961-1990 | Climate difference |
|---|---|---|---|---|---|
| Cedar City AP | United States | 149 km (93 mi) | 10.3 C (50.5 F) | 292.4 mm (11.5 in) | 0.58 |
| Pedernal 9 E | United States | 646 km (401 mi) | 10.2 C (50.3 F) | 281.0 mm (11.1 in) | 0.63 |
| Keams Canyon | United States | 257 km (160 mi) | 10.0 C (50.1 F) | 248.6 mm (9.8 in) | 0.67 |
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 2026-10-13 (13 October 2026). Records are computed by this site and are not official.
Data as of . Last revised (2026-10-13).