New Boston Dam 17 Weather Records (USC00116080)
Record envelope, standing records and threshold days for New Boston Dam 17 (USC00116080), Illinois, United States, with 89 years of record.
Key Facts for New Boston Dam 17
- New Boston Dam 17 (USC00116080) is a weather station in Illinois, United States at 41.19 latitude and -91.06 longitude, 167 m (547 ft) above sea level.
- The station reports from 1938 to 2026, 89 years of record.
- 1,464 records set at New Boston Dam 17 still stand.
- Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
- New Boston Dam 17 set a daily record high minimum temperature of 18.3 C (64.9 F) on 13 October 2026 (provisional).
Provisional Records
Records set in the last 60 days are provisional until they clear the revision window.
About the Station
- Location: Illinois, United States, 41.19 latitude, -91.06 longitude.
- Elevation: 167 m (547 ft).
- Period of record: 1938 to 2026, 89 years.
- Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
17 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 17.8 C (64.0 F) | -32.2 C (-26.0 F) | 15.0 C (59.0 F) | -24.4 C (-11.9 F) |
| Feb | 23.9 C (75.0 F) | -31.7 C (-25.1 F) | 20.0 C (68.0 F) | -15.0 C (5.0 F) |
| Mar | 30.0 C (86.0 F) | -25.6 C (-14.1 F) | 30.0 C (86.0 F) | -12.8 C (9.0 F) |
| Apr | 31.1 C (88.0 F) | -8.3 C (17.1 F) | 28.9 C (84.0 F) | 0.0 C (32.0 F) |
| May | 43.9 C (111.0 F) | -2.2 C (28.0 F) | 35.0 C (95.0 F) | 3.3 C (37.9 F) |
| Jun | 37.2 C (99.0 F) | -0.6 C (30.9 F) | 33.9 C (93.0 F) | 11.1 C (52.0 F) |
| Jul | 40.6 C (105.1 F) | 9.4 C (48.9 F) | 37.2 C (99.0 F) | 12.8 C (55.0 F) |
| Aug | 39.4 C (102.9 F) | 7.8 C (46.0 F) | 33.3 C (91.9 F) | 12.8 C (55.0 F) |
| Sep | 37.2 C (99.0 F) | -1.1 C (30.0 F) | 36.7 C (98.1 F) | 10.6 C (51.1 F) |
| Oct | 33.3 C (91.9 F) | -6.1 C (21.0 F) | 32.2 C (90.0 F) | 7.2 C (45.0 F) |
| Nov | 27.8 C (82.0 F) | -14.4 C (6.1 F) | n/a | n/a |
| Dec | 22.8 C (73.0 F) | -27.8 C (-18.0 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1938 | 29 |
| 1939 | 50 |
| 1940 | 46 |
| 1941 | 27 |
| 1942 | 43 |
| 1943 | 33 |
| 1944 | 24 |
| 1945 | 44 |
| 1946 | 36 |
| 1947 | 59 |
| 1948 | 12 |
| 1968 | 1 |
| 1970 | 1 |
| 1976 | 1 |
| 1979 | 5 |
| 1997 | 33 |
| 1998 | 40 |
| 1999 | 35 |
| 2000 | 41 |
| 2001 | 40 |
| 2002 | 31 |
| 2003 | 28 |
| 2004 | 43 |
| 2005 | 30 |
| 2006 | 45 |
| 2007 | 35 |
| 2008 | 20 |
| 2009 | 26 |
| 2010 | 21 |
| 2011 | 27 |
| 2012 | 53 |
| 2013 | 45 |
| 2014 | 49 |
| 2015 | 40 |
| 2016 | 29 |
| 2017 | 51 |
| 2018 | 51 |
| 2019 | 36 |
| 2020 | 23 |
| 2021 | 28 |
| 2022 | 38 |
| 2023 | 23 |
| 2024 | 34 |
| 2025 | 33 |
| 2026 | 25 |
All-Time Record Progression
6 new records| Date | Kind | Detail |
|---|---|---|
| 1971-01-04 | Record daily snowfall | Record daily snowfall 30.5 cm (12.0 in) |
| 1979-01-13 | Record snow depth | Record snow depth 63.5 cm (25.0 in) |
| 1979-01-14 | Record snow depth | Record snow depth 71.1 cm (28.0 in) |
| 1979-01-19 | Record snow depth | Record snow depth 76.2 cm (30.0 in) |
| 2019-01-31 | Record low maximum temperature | Record low maximum temperature -22.2 C (-8.0 F) |
| 2019-01-31 | Record low minimum temperature | Record low minimum temperature -32.2 C (-26.0 F) |
Wettest Day of Each Month
Aug: 189.7 mm (7.5 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 40.6 mm (1.6 in) | 18 January 2020 |
| Feb | 49.5 mm (1.9 in) | 21 February 1997 |
| Mar | 115.3 mm (4.5 in) | 13 March 2006 |
| Apr | 84.8 mm (3.3 in) | 24 April 1976 |
| May | 128.0 mm (5.0 in) | 1 May 2003 |
| Jun | 106.7 mm (4.2 in) | 22 June 2007 |
| Jul | 113.5 mm (4.5 in) | 5 July 1948 |
| Aug | 189.7 mm (7.5 in) | 17 August 1939 |
| Sep | 108.0 mm (4.3 in) | 21 September 1947 |
| Oct | 70.6 mm (2.8 in) | 13 October 1966 |
| Nov | 52.3 mm (2.1 in) | 1 November 1984 |
| Dec | 91.4 mm (3.6 in) | 27 December 1942 |
Period of Record Coverage
1938 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1938 | 162 | 44% | No |
| 1939 | 215 | 59% | No |
| 1940 | 363 | 99% | Yes |
| 1941 | 353 | 97% | Yes |
| 1942 | 357 | 98% | Yes |
| 1943 | 361 | 99% | Yes |
| 1944 | 318 | 87% | No |
| 1945 | 346 | 95% | Yes |
| 1946 | 350 | 96% | Yes |
| 1947 | 361 | 99% | Yes |
| 1948 | 123 | 34% | No |
| 1968 | 30 | 8% | No |
| 1970 | 16 | 4% | No |
| 1976 | 53 | 14% | No |
| 1979 | 60 | 16% | No |
| 1997 | 244 | 67% | No |
| 1998 | 365 | 100% | Yes |
| 1999 | 364 | 100% | Yes |
| 2000 | 366 | 100% | Yes |
| 2001 | 364 | 100% | Yes |
| 2002 | 363 | 99% | Yes |
| 2003 | 365 | 100% | Yes |
| 2004 | 364 | 99% | Yes |
| 2005 | 364 | 100% | Yes |
| 2006 | 365 | 100% | Yes |
| 2007 | 362 | 99% | Yes |
| 2008 | 362 | 99% | Yes |
| 2009 | 362 | 99% | Yes |
| 2010 | 365 | 100% | Yes |
| 2011 | 361 | 99% | Yes |
| 2012 | 356 | 97% | Yes |
| 2013 | 363 | 99% | Yes |
| 2014 | 359 | 98% | Yes |
| 2015 | 362 | 99% | Yes |
| 2016 | 361 | 99% | Yes |
| 2017 | 361 | 99% | Yes |
| 2018 | 352 | 96% | Yes |
| 2019 | 359 | 98% | Yes |
| 2020 | 366 | 100% | Yes |
| 2021 | 361 | 99% | Yes |
| 2022 | 353 | 97% | Yes |
| 2023 | 351 | 96% | Yes |
| 2024 | 342 | 93% | Yes |
| 2025 | 336 | 92% | Yes |
| 2026 | 261 | 72% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 13 October 2026 | New Boston Dam 17, US | daily high min (Provisional) | 18.3 C (64.9 F) | 3.9 C (7.0 F) | 84 years | 40 of 100 (Notable) |
| 11 October 2026 | New Boston Dam 17, US | daily high max (Tie, Provisional) | 28.3 C (82.9 F) | tie | 5 years | 2 of 100 (Routine) |
| 9 October 2026 | New Boston Dam 17, US | daily high max (Provisional) | 32.2 C (90.0 F) | 2.8 C (5.0 F) | 11 years | 15 of 100 (Routine) |
| 2 October 2026 | New Boston Dam 17, US | monthly rain (Provisional) | 72.4 mm (2.9 in) | 1.8 mm (0.07 in) | 59 years | 36 of 100 (Notable) |
| 20 September 2026 | New Boston Dam 17, US | daily rain (Provisional) | 43.2 mm (1.7 in) | 9.7 mm (0.38 in) | 60 years | 32 of 100 (Routine) |
| 19 September 2026 | New Boston Dam 17, US | daily high min (Tie, Provisional) | 19.4 C (66.9 F) | tie | 85 years | 8 of 100 (Routine) |
| 18 September 2026 | New Boston Dam 17, US | daily high max (Provisional) | 36.7 C (98.1 F) | 2.3 C (4.1 F) | 8 years | 14 of 100 (Routine) |
| 9 September 2026 | New Boston Dam 17, US | daily rain (Provisional) | 69.9 mm (2.8 in) | 42.0 mm (1.7 in) | 29 years | 44 of 100 (Notable) |
| 6 September 2026 | New Boston Dam 17, US | daily high max (Provisional) | 36.7 C (98.1 F) | 1.7 C (3.1 F) | 11 years | 14 of 100 (Routine) |
| 5 September 2026 | New Boston Dam 17, US | daily high max (Provisional) | 36.7 C (98.1 F) | 1.7 C (3.1 F) | 11 years | 14 of 100 (Routine) |
| 5 September 2026 | New Boston Dam 17, US | daily high min (Provisional) | 23.3 C (73.9 F) | 1.1 C (2.0 F) | 8 years | 12 of 100 (Routine) |
| 4 September 2026 | New Boston Dam 17, US | daily high min (Provisional) | 23.9 C (75.0 F) | 2.2 C (4.0 F) | 79 years | 35 of 100 (Notable) |
| 3 September 2026 | New Boston Dam 17, US | daily high min (Provisional) | 23.9 C (75.0 F) | 0.6 C (1.1 F) | 15 years | 13 of 100 (Routine) |
| 16 August 2026 | New Boston Dam 17, US | daily rain | 61.2 mm (2.4 in) | 7.6 mm (0.30 in) | 32 years | 21 of 100 (Routine) |
| 15 August 2026 | New Boston Dam 17, US | daily rain | 85.1 mm (3.4 in) | 49.8 mm (2.0 in) | 1 year | 39 of 100 (Notable) |
| 15 August 2026 | New Boston Dam 17, US | daily high min (Tie) | 22.8 C (73.0 F) | tie | 19 years | 3 of 100 (Routine) |
| 6 August 2026 | New Boston Dam 17, US | daily low max | 23.9 C (75.0 F) | 0.5 C (0.9 F) | 28 years | 17 of 100 (Routine) |
| 2 August 2026 | New Boston Dam 17, US | daily low max | 22.8 C (73.0 F) | 2.8 C (5.0 F) | 16 years | 20 of 100 (Routine) |
| 1 August 2026 | New Boston Dam 17, US | daily rain | 50.0 mm (2.0 in) | 11.9 mm (0.5 in) | 32 years | 24 of 100 (Routine) |
| 27 July 2026 | New Boston Dam 17, US | daily high min | 24.4 C (75.9 F) | 0.5 C (0.9 F) | 5 years | 10 of 100 (Routine) |
Climate Trend
33 complete years, 1940 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1940 | 10.3 C | -0.61 C |
| 1941 | 12.0 C | +1.03 C |
| 1942 | 10.9 C | -0.09 C |
| 1943 | 10.2 C | -0.72 C |
| 1947 | 10.3 C | -0.69 C |
| 1998 | 12.0 C | +1.10 C |
| 1999 | 11.1 C | +0.19 C |
| 2000 | 10.5 C | -0.40 C |
| 2001 | 10.5 C | -0.41 C |
| 2002 | 11.1 C | +0.14 C |
| 2003 | 10.3 C | -0.60 C |
| 2004 | 10.7 C | -0.20 C |
| 2005 | 11.4 C | +0.44 C |
| 2006 | 11.7 C | +0.72 C |
| 2007 | 11.2 C | +0.27 C |
| 2008 | 9.6 C | -1.35 C |
| 2009 | 10.0 C | -0.99 C |
| 2010 | 11.0 C | +0.07 C |
| 2011 | 10.9 C | -0.03 C |
| 2012 | 12.4 C | +1.48 C |
| 2013 | 9.8 C | -1.17 C |
| 2014 | 8.7 C | -2.22 C |
| 2015 | 10.9 C | -0.05 C |
| 2016 | 12.1 C | +1.17 C |
| 2017 | 11.5 C | +0.54 C |
| 2018 | 10.4 C | -0.53 C |
| 2019 | 10.2 C | -0.76 C |
| 2020 | 11.2 C | +0.26 C |
| 2021 | 11.5 C | +0.58 C |
| 2022 | 10.4 C | -0.56 C |
| 2023 | 12.0 C | +1.10 C |
| 2024 | 12.5 C | +1.60 C |
| 2025 | 11.7 C | +0.73 C |
The fitted trend in annual mean temperature here over 1940 to 2025 is 0.05 C (-0.07 to 0.17) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.1 to 0.3) per decade. The slope is a straight line fitted to 33 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.05 C (-0.07 to 0.17) per decade | 0.1 F (-0.1 to 0.3) per decade | 1940 to 2025 | 33 | Not clearly different from zero |
| Mean daily maximum | 0.09 C (-0.03 to 0.22) per decade | 0.2 F (-0.1 to 0.4) per decade | 1940 to 2025 | 33 | Not clearly different from zero |
| Mean daily minimum | 0.0 C (-0.1 to 0.1) per decade | 0.0 F (-0.2 to 0.2) per decade | 1940 to 2025 | 33 | Not clearly different from zero |
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
1938 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 43.9 C (111.0 F) | 1939 | 36.1 C (97.0 F) | 45 |
| Coldest night (TNn) | -32.2 C (-26.0 F) | 2019 | -22.8 C (-9.0 F) | 45 |
| Wettest day (Rx1day) | 189.7 mm (7.5 in) | 1939 | 61.0 mm (2.4 in) | 89 |
| Wettest five days (Rx5day) | 205.7 mm (8.1 in) | 1939 | 99.3 mm (3.9 in) | 89 |
| Longest dry spell (CDD) | 75 days | 1952 | 24 days | 89 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1938 | 38.9 C (102.0 F) |
| 1939 | 43.9 C (111.0 F) |
| 1940 | 38.9 C (102.0 F) |
| 1941 | 37.8 C (100.0 F) |
| 1942 | 35.0 C (95.0 F) |
| 1943 | 35.0 C (95.0 F) |
| 1944 | 35.0 C (95.0 F) |
| 1945 | 36.7 C (98.1 F) |
| 1946 | 35.0 C (95.0 F) |
| 1947 | 37.8 C (100.0 F) |
| 1948 | 27.8 C (82.0 F) |
| 1949 | n/a |
| 1950 | n/a |
| 1951 | n/a |
| 1952 | n/a |
| 1953 | n/a |
| 1954 | n/a |
| 1955 | n/a |
| 1956 | n/a |
| 1957 | n/a |
| 1958 | n/a |
| 1959 | n/a |
| 1960 | n/a |
| 1961 | n/a |
| 1962 | n/a |
| 1963 | n/a |
| 1964 | n/a |
| 1965 | n/a |
| 1966 | n/a |
| 1967 | n/a |
| 1968 | 26.7 C (80.1 F) |
| 1969 | n/a |
| 1970 | 32.2 C (90.0 F) |
| 1971 | n/a |
| 1972 | n/a |
| 1973 | n/a |
| 1974 | n/a |
| 1975 | n/a |
| 1976 | 27.2 C (81.0 F) |
| 1977 | n/a |
| 1978 | n/a |
| 1979 | 31.1 C (88.0 F) |
| 1980 | n/a |
| 1981 | n/a |
| 1982 | n/a |
| 1983 | n/a |
| 1984 | n/a |
| 1985 | n/a |
| 1986 | n/a |
| 1987 | n/a |
| 1988 | n/a |
| 1989 | n/a |
| 1990 | n/a |
| 1991 | n/a |
| 1992 | n/a |
| 1993 | n/a |
| 1994 | n/a |
| 1995 | n/a |
| 1996 | n/a |
| 1997 | 36.1 C (97.0 F) |
| 1998 | 35.6 C (96.1 F) |
| 1999 | 38.3 C (100.9 F) |
| 2000 | 36.7 C (98.1 F) |
| 2001 | 35.6 C (96.1 F) |
| 2002 | 37.2 C (99.0 F) |
| 2003 | 36.7 C (98.1 F) |
| 2004 | 34.4 C (93.9 F) |
| 2005 | 38.9 C (102.0 F) |
| 2006 | 37.8 C (100.0 F) |
| 2007 | 34.4 C (93.9 F) |
| 2008 | 34.4 C (93.9 F) |
| 2009 | 36.1 C (97.0 F) |
| 2010 | 36.7 C (98.1 F) |
| 2011 | 40.6 C (105.1 F) |
| 2012 | 40.0 C (104.0 F) |
| 2013 | 37.8 C (100.0 F) |
| 2014 | 34.4 C (93.9 F) |
| 2015 | 35.0 C (95.0 F) |
| 2016 | 35.6 C (96.1 F) |
| 2017 | 35.6 C (96.1 F) |
| 2018 | 36.1 C (97.0 F) |
| 2019 | 35.6 C (96.1 F) |
| 2020 | 37.2 C (99.0 F) |
| 2021 | 35.0 C (95.0 F) |
| 2022 | 37.2 C (99.0 F) |
| 2023 | 39.4 C (102.9 F) |
| 2024 | 35.0 C (95.0 F) |
| 2025 | 37.2 C (99.0 F) |
| 2026 | 37.2 C (99.0 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1938 | -16.7 C (1.9 F) |
| 1939 | -17.2 C (1.0 F) |
| 1940 | -26.1 C (-15.0 F) |
| 1941 | -17.2 C (1.0 F) |
| 1942 | -24.4 C (-11.9 F) |
| 1943 | -26.1 C (-15.0 F) |
| 1944 | -21.7 C (-7.1 F) |
| 1945 | -21.1 C (-6.0 F) |
| 1946 | -20.6 C (-5.1 F) |
| 1947 | -25.0 C (-13.0 F) |
| 1948 | -21.1 C (-6.0 F) |
| 1949 | n/a |
| 1950 | n/a |
| 1951 | n/a |
| 1952 | n/a |
| 1953 | n/a |
| 1954 | n/a |
| 1955 | n/a |
| 1956 | n/a |
| 1957 | n/a |
| 1958 | n/a |
| 1959 | n/a |
| 1960 | n/a |
| 1961 | n/a |
| 1962 | n/a |
| 1963 | n/a |
| 1964 | n/a |
| 1965 | n/a |
| 1966 | n/a |
| 1967 | n/a |
| 1968 | -10.0 C (14.0 F) |
| 1969 | n/a |
| 1970 | 11.7 C (53.1 F) |
| 1971 | n/a |
| 1972 | n/a |
| 1973 | n/a |
| 1974 | n/a |
| 1975 | n/a |
| 1976 | -23.9 C (-11.0 F) |
| 1977 | n/a |
| 1978 | n/a |
| 1979 | -6.7 C (19.9 F) |
| 1980 | n/a |
| 1981 | n/a |
| 1982 | n/a |
| 1983 | n/a |
| 1984 | n/a |
| 1985 | n/a |
| 1986 | n/a |
| 1987 | n/a |
| 1988 | n/a |
| 1989 | n/a |
| 1990 | n/a |
| 1991 | n/a |
| 1992 | n/a |
| 1993 | n/a |
| 1994 | n/a |
| 1995 | n/a |
| 1996 | n/a |
| 1997 | -11.1 C (12.0 F) |
| 1998 | -19.4 C (-2.9 F) |
| 1999 | -29.4 C (-20.9 F) |
| 2000 | -27.8 C (-18.0 F) |
| 2001 | -25.0 C (-13.0 F) |
| 2002 | -23.3 C (-9.9 F) |
| 2003 | -20.6 C (-5.1 F) |
| 2004 | -23.3 C (-9.9 F) |
| 2005 | -21.7 C (-7.1 F) |
| 2006 | -21.7 C (-7.1 F) |
| 2007 | -21.1 C (-6.0 F) |
| 2008 | -23.3 C (-9.9 F) |
| 2009 | -31.7 C (-25.1 F) |
| 2010 | -25.0 C (-13.0 F) |
| 2011 | -21.7 C (-7.1 F) |
| 2012 | -15.0 C (5.0 F) |
| 2013 | -24.4 C (-11.9 F) |
| 2014 | -28.3 C (-18.9 F) |
| 2015 | -26.1 C (-15.0 F) |
| 2016 | -21.7 C (-7.1 F) |
| 2017 | -21.1 C (-6.0 F) |
| 2018 | -27.8 C (-18.0 F) |
| 2019 | -32.2 C (-26.0 F) |
| 2020 | -21.7 C (-7.1 F) |
| 2021 | -26.1 C (-15.0 F) |
| 2022 | -22.8 C (-9.0 F) |
| 2023 | -18.3 C (-0.9 F) |
| 2024 | -26.7 C (-16.1 F) |
| 2025 | -23.3 C (-9.9 F) |
| 2026 | -24.4 C (-11.9 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1938 | 77.5 mm (3.1 in) |
| 1939 | 189.7 mm (7.5 in) |
| 1940 | 43.9 mm (1.7 in) |
| 1941 | 33.0 mm (1.3 in) |
| 1942 | 91.4 mm (3.6 in) |
| 1943 | 46.2 mm (1.8 in) |
| 1944 | 50.3 mm (2.0 in) |
| 1945 | 39.9 mm (1.6 in) |
| 1946 | 76.5 mm (3.0 in) |
| 1947 | 108.0 mm (4.3 in) |
| 1948 | 113.5 mm (4.5 in) |
| 1949 | 49.8 mm (2.0 in) |
| 1950 | 52.8 mm (2.1 in) |
| 1951 | 96.8 mm (3.8 in) |
| 1952 | 59.7 mm (2.4 in) |
| 1953 | 51.8 mm (2.0 in) |
| 1954 | 80.5 mm (3.2 in) |
| 1955 | 44.2 mm (1.7 in) |
| 1956 | 37.3 mm (1.5 in) |
| 1957 | 38.1 mm (1.5 in) |
| 1958 | 84.3 mm (3.3 in) |
| 1959 | 63.8 mm (2.5 in) |
| 1960 | 48.3 mm (1.9 in) |
| 1961 | 94.0 mm (3.7 in) |
| 1962 | 53.3 mm (2.1 in) |
| 1963 | 37.1 mm (1.5 in) |
| 1964 | 58.4 mm (2.3 in) |
| 1965 | 110.0 mm (4.3 in) |
| 1966 | 70.6 mm (2.8 in) |
| 1967 | 52.1 mm (2.1 in) |
| 1968 | 64.3 mm (2.5 in) |
| 1969 | 81.3 mm (3.2 in) |
| 1970 | 61.0 mm (2.4 in) |
| 1971 | 56.6 mm (2.2 in) |
| 1972 | 63.0 mm (2.5 in) |
| 1973 | 90.2 mm (3.6 in) |
| 1974 | 58.4 mm (2.3 in) |
| 1975 | 38.6 mm (1.5 in) |
| 1976 | 84.8 mm (3.3 in) |
| 1977 | 91.7 mm (3.6 in) |
| 1978 | 51.3 mm (2.0 in) |
| 1979 | 46.2 mm (1.8 in) |
| 1980 | 77.7 mm (3.1 in) |
| 1981 | 50.8 mm (2.0 in) |
| 1982 | 66.3 mm (2.6 in) |
| 1983 | 50.8 mm (2.0 in) |
| 1984 | 57.2 mm (2.3 in) |
| 1985 | 55.9 mm (2.2 in) |
| 1986 | 12.7 mm (0.5 in) |
| 1987 | 26.7 mm (1.1 in) |
| 1988 | 41.9 mm (1.6 in) |
| 1989 | 52.3 mm (2.1 in) |
| 1990 | 92.7 mm (3.6 in) |
| 1991 | 31.5 mm (1.2 in) |
| 1992 | 69.9 mm (2.8 in) |
| 1993 | 54.4 mm (2.1 in) |
| 1994 | 34.5 mm (1.4 in) |
| 1995 | 55.6 mm (2.2 in) |
| 1996 | 61.0 mm (2.4 in) |
| 1997 | 50.3 mm (2.0 in) |
| 1998 | 59.4 mm (2.3 in) |
| 1999 | 86.4 mm (3.4 in) |
| 2000 | 88.4 mm (3.5 in) |
| 2001 | 62.0 mm (2.4 in) |
| 2002 | 59.2 mm (2.3 in) |
| 2003 | 128.0 mm (5.0 in) |
| 2004 | 64.3 mm (2.5 in) |
| 2005 | 28.2 mm (1.1 in) |
| 2006 | 115.3 mm (4.5 in) |
| 2007 | 106.7 mm (4.2 in) |
| 2008 | 91.2 mm (3.6 in) |
| 2009 | 61.2 mm (2.4 in) |
| 2010 | 48.3 mm (1.9 in) |
| 2011 | 56.6 mm (2.2 in) |
| 2012 | 64.8 mm (2.6 in) |
| 2013 | 70.4 mm (2.8 in) |
| 2014 | 74.9 mm (2.9 in) |
| 2015 | 69.9 mm (2.8 in) |
| 2016 | 99.6 mm (3.9 in) |
| 2017 | 81.8 mm (3.2 in) |
| 2018 | 121.9 mm (4.8 in) |
| 2019 | 79.2 mm (3.1 in) |
| 2020 | 40.6 mm (1.6 in) |
| 2021 | 83.8 mm (3.3 in) |
| 2022 | 49.5 mm (1.9 in) |
| 2023 | 47.0 mm (1.9 in) |
| 2024 | 48.3 mm (1.9 in) |
| 2025 | 80.8 mm (3.2 in) |
| 2026 | 85.1 mm (3.4 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1938 | 114.8 mm (4.5 in) |
| 1939 | 205.7 mm (8.1 in) |
| 1940 | 99.3 mm (3.9 in) |
| 1941 | 80.5 mm (3.2 in) |
| 1942 | 93.9 mm (3.7 in) |
| 1943 | 82.2 mm (3.2 in) |
| 1944 | 67.2 mm (2.6 in) |
| 1945 | 74.7 mm (2.9 in) |
| 1946 | 107.2 mm (4.2 in) |
| 1947 | 109.3 mm (4.3 in) |
| 1948 | 113.5 mm (4.5 in) |
| 1949 | 94.5 mm (3.7 in) |
| 1950 | 113.5 mm (4.5 in) |
| 1951 | 121.2 mm (4.8 in) |
| 1952 | 70.1 mm (2.8 in) |
| 1953 | 85.8 mm (3.4 in) |
| 1954 | 96.8 mm (3.8 in) |
| 1955 | 74.5 mm (2.9 in) |
| 1956 | 68.6 mm (2.7 in) |
| 1957 | 57.2 mm (2.3 in) |
| 1958 | 143.2 mm (5.6 in) |
| 1959 | 139.5 mm (5.5 in) |
| 1960 | 77.7 mm (3.1 in) |
| 1961 | 144.8 mm (5.7 in) |
| 1962 | 95.5 mm (3.8 in) |
| 1963 | 60.0 mm (2.4 in) |
| 1964 | 78.7 mm (3.1 in) |
| 1965 | 167.6 mm (6.6 in) |
| 1966 | 110.2 mm (4.3 in) |
| 1967 | 78.9 mm (3.1 in) |
| 1968 | 77.3 mm (3.0 in) |
| 1969 | 103.6 mm (4.1 in) |
| 1970 | 104.2 mm (4.1 in) |
| 1971 | 60.7 mm (2.4 in) |
| 1972 | 74.0 mm (2.9 in) |
| 1973 | 148.1 mm (5.8 in) |
| 1974 | 66.1 mm (2.6 in) |
| 1975 | 56.0 mm (2.2 in) |
| 1976 | 120.5 mm (4.7 in) |
| 1977 | 173.9 mm (6.8 in) |
| 1978 | 62.5 mm (2.5 in) |
| 1979 | 91.0 mm (3.6 in) |
| 1980 | 129.7 mm (5.1 in) |
| 1981 | 96.5 mm (3.8 in) |
| 1982 | 133.0 mm (5.2 in) |
| 1983 | 99.5 mm (3.9 in) |
| 1984 | 123.8 mm (4.9 in) |
| 1985 | 100.5 mm (4.0 in) |
| 1986 | 25.2 mm (1.0 in) |
| 1987 | 42.4 mm (1.7 in) |
| 1988 | 69.8 mm (2.7 in) |
| 1989 | 126.2 mm (5.0 in) |
| 1990 | 148.8 mm (5.9 in) |
| 1991 | 69.9 mm (2.8 in) |
| 1992 | 91.4 mm (3.6 in) |
| 1993 | 114.1 mm (4.5 in) |
| 1994 | 47.5 mm (1.9 in) |
| 1995 | 101.4 mm (4.0 in) |
| 1996 | 118.2 mm (4.7 in) |
| 1997 | 69.4 mm (2.7 in) |
| 1998 | 100.8 mm (4.0 in) |
| 1999 | 113.1 mm (4.5 in) |
| 2000 | 109.5 mm (4.3 in) |
| 2001 | 92.5 mm (3.6 in) |
| 2002 | 68.9 mm (2.7 in) |
| 2003 | 168.1 mm (6.6 in) |
| 2004 | 103.2 mm (4.1 in) |
| 2005 | 45.7 mm (1.8 in) |
| 2006 | 124.7 mm (4.9 in) |
| 2007 | 140.0 mm (5.5 in) |
| 2008 | 176.8 mm (7.0 in) |
| 2009 | 91.4 mm (3.6 in) |
| 2010 | 80.0 mm (3.1 in) |
| 2011 | 67.8 mm (2.7 in) |
| 2012 | 104.9 mm (4.1 in) |
| 2013 | 93.7 mm (3.7 in) |
| 2014 | 84.4 mm (3.3 in) |
| 2015 | 111.2 mm (4.4 in) |
| 2016 | 112.8 mm (4.4 in) |
| 2017 | 84.4 mm (3.3 in) |
| 2018 | 132.6 mm (5.2 in) |
| 2019 | 127.8 mm (5.0 in) |
| 2020 | 98.6 mm (3.9 in) |
| 2021 | 111.8 mm (4.4 in) |
| 2022 | 53.3 mm (2.1 in) |
| 2023 | 70.4 mm (2.8 in) |
| 2024 | 101.4 mm (4.0 in) |
| 2025 | 158.5 mm (6.2 in) |
| 2026 | 146.3 mm (5.8 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1938 | 13 days |
| 1939 | 24 days |
| 1940 | 25 days |
| 1941 | 19 days |
| 1942 | 28 days |
| 1943 | 47 days |
| 1944 | 25 days |
| 1945 | 24 days |
| 1946 | 22 days |
| 1947 | 28 days |
| 1948 | 23 days |
| 1949 | 23 days |
| 1950 | 31 days |
| 1951 | 16 days |
| 1952 | 75 days |
| 1953 | 23 days |
| 1954 | 23 days |
| 1955 | 20 days |
| 1956 | 24 days |
| 1957 | 28 days |
| 1958 | 26 days |
| 1959 | 20 days |
| 1960 | 14 days |
| 1961 | 14 days |
| 1962 | 20 days |
| 1963 | 19 days |
| 1964 | 35 days |
| 1965 | 20 days |
| 1966 | 26 days |
| 1967 | 23 days |
| 1968 | 17 days |
| 1969 | 32 days |
| 1970 | 16 days |
| 1971 | 24 days |
| 1972 | 13 days |
| 1973 | 18 days |
| 1974 | 25 days |
| 1975 | 16 days |
| 1976 | 26 days |
| 1977 | 25 days |
| 1978 | 16 days |
| 1979 | 39 days |
| 1980 | 27 days |
| 1981 | 24 days |
| 1982 | 18 days |
| 1983 | 20 days |
| 1984 | 29 days |
| 1985 | 20 days |
| 1986 | 25 days |
| 1987 | 9 days |
| 1988 | 35 days |
| 1989 | 25 days |
| 1990 | 14 days |
| 1991 | 32 days |
| 1992 | 22 days |
| 1993 | 24 days |
| 1994 | 15 days |
| 1995 | 35 days |
| 1996 | 22 days |
| 1997 | 21 days |
| 1998 | 16 days |
| 1999 | 37 days |
| 2000 | 18 days |
| 2001 | 19 days |
| 2002 | 29 days |
| 2003 | 28 days |
| 2004 | 22 days |
| 2005 | 24 days |
| 2006 | 28 days |
| 2007 | 27 days |
| 2008 | 14 days |
| 2009 | 27 days |
| 2010 | 26 days |
| 2011 | 20 days |
| 2012 | 24 days |
| 2013 | 46 days |
| 2014 | 20 days |
| 2015 | 24 days |
| 2016 | 24 days |
| 2017 | 20 days |
| 2018 | 17 days |
| 2019 | 15 days |
| 2020 | 25 days |
| 2021 | 17 days |
| 2022 | 26 days |
| 2023 | 22 days |
| 2024 | 19 days |
| 2025 | 27 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
33 years with a frostAcross 33 years with a frost, the median last spring frost at New Boston Dam 17 falls on 14 April and the median first autumn frost on 24 October, which leaves a median of 187 days between them.
Fitted over all years, the growing season changes by +1.1 days per decade at this station.
| Measure | Median, all years | Earliest period | Recent period (1943 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 14 April | n/a | 16 April | n/a | 0.0 days per decade |
| First autumn frost | 24 October | n/a | 23 October | n/a | +1.1 days per decade |
| Growing days | 187 days | n/a | 187 days | n/a | +1.1 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
83 years, 1940 to 2025A day with at least 62.3 mm (2.5 in) of rain is expected about once in 2 years. A day with at least 140.0 mm (5.5 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 62.3 mm (2.5 in) | |
| 5 years | 83.3 mm (3.3 in) | |
| 10 years | 97.1 mm (3.8 in) | |
| 25 years | 114.4 mm (4.5 in) | |
| 50 years | 127.3 mm (5.0 in) | |
| 100 years | 140.0 mm (5.5 in) | Longer than the 83 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, 83 years of values from 1940 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: 128.0 mm (5.0 in) in 2003; 121.9 mm (4.8 in) in 2018; 115.3 mm (4.5 in) in 2006.
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).