Boundary Dam Weather Records (USC00450844)
Record envelope, standing records and threshold days for Boundary Dam (USC00450844), Washington, United States, with 62 years of record.
Key Facts for Boundary Dam
- Boundary Dam (USC00450844) is a weather station in Washington, United States at 48.99 latitude and -117.35 longitude, 560 m (1,837 ft) above sea level.
- The station reports from 1965 to 2026, 62 years of record.
- 1,464 records set at Boundary Dam still stand.
- Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
- Boundary Dam tied a daily record low maximum temperature of 16.1 C (61.0 F) on 8 September 2026 (provisional).
Provisional Records
Records set in the last 60 days are provisional until they clear the revision window.
About the Station
- Location: Washington, United States, 48.99 latitude, -117.35 longitude.
- Elevation: 560 m (1,837 ft).
- Period of record: 1965 to 2026, 62 years.
- Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
13 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 10.0 C (50.0 F) | -28.9 C (-20.0 F) | 3.9 C (39.0 F) | -14.4 C (6.1 F) |
| Feb | 14.4 C (57.9 F) | -26.1 C (-15.0 F) | 8.3 C (46.9 F) | -13.9 C (7.0 F) |
| Mar | 22.8 C (73.0 F) | -20.6 C (-5.1 F) | 17.8 C (64.0 F) | -8.9 C (16.0 F) |
| Apr | 32.2 C (90.0 F) | -10.0 C (14.0 F) | 22.8 C (73.0 F) | -6.7 C (19.9 F) |
| May | 35.6 C (96.1 F) | -5.6 C (21.9 F) | 34.4 C (93.9 F) | 0.6 C (33.1 F) |
| Jun | 43.9 C (111.0 F) | -1.1 C (30.0 F) | 32.8 C (91.0 F) | 1.7 C (35.1 F) |
| Jul | 43.3 C (109.9 F) | 1.1 C (34.0 F) | 37.2 C (99.0 F) | 5.6 C (42.1 F) |
| Aug | 40.0 C (104.0 F) | 0.0 C (32.0 F) | 37.2 C (99.0 F) | 4.4 C (39.9 F) |
| Sep | 37.8 C (100.0 F) | -5.6 C (21.9 F) | 28.9 C (84.0 F) | 0.0 C (32.0 F) |
| Oct | 26.7 C (80.1 F) | -12.8 C (9.0 F) | 20.6 C (69.1 F) | -3.9 C (25.0 F) |
| Nov | 16.1 C (61.0 F) | -28.3 C (-18.9 F) | n/a | n/a |
| Dec | 11.7 C (53.1 F) | -33.3 C (-27.9 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1965 | 19 |
| 1966 | 45 |
| 1967 | 29 |
| 1968 | 22 |
| 1969 | 30 |
| 1970 | 21 |
| 1974 | 27 |
| 1975 | 27 |
| 1976 | 25 |
| 1977 | 21 |
| 1978 | 17 |
| 1979 | 37 |
| 1980 | 45 |
| 1981 | 30 |
| 1982 | 21 |
| 1983 | 38 |
| 1984 | 51 |
| 1985 | 48 |
| 1986 | 34 |
| 1987 | 38 |
| 1988 | 31 |
| 1989 | 18 |
| 1990 | 24 |
| 1991 | 19 |
| 1992 | 38 |
| 1993 | 29 |
| 1994 | 25 |
| 1995 | 18 |
| 1996 | 23 |
| 1997 | 12 |
| 1998 | 25 |
| 1999 | 21 |
| 2000 | 9 |
| 2001 | 20 |
| 2002 | 23 |
| 2003 | 23 |
| 2004 | 8 |
| 2005 | 7 |
| 2006 | 17 |
| 2007 | 28 |
| 2008 | 70 |
| 2009 | 13 |
| 2010 | 15 |
| 2011 | 17 |
| 2012 | 8 |
| 2013 | 23 |
| 2014 | 36 |
| 2015 | 28 |
| 2016 | 28 |
| 2017 | 8 |
| 2018 | 13 |
| 2019 | 20 |
| 2020 | 18 |
| 2021 | 33 |
| 2022 | 14 |
| 2023 | 17 |
| 2024 | 31 |
| 2025 | 18 |
| 2026 | 11 |
All-Time Record Progression
6 new records| Date | Kind | Detail |
|---|---|---|
| 2015-06-29 | Record high maximum temperature | Record high maximum temperature 40.6 C (105.1 F) |
| 2021-06-29 | Record high maximum temperature | Record high maximum temperature 42.2 C (108.0 F) |
| 2021-06-30 | Record high maximum temperature | Record high maximum temperature 43.9 C (111.0 F) |
| 2021-06-30 | Record high minimum temperature | Record high minimum temperature 18.3 C (64.9 F) |
| 2021-07-01 | Record high minimum temperature | Record high minimum temperature 18.9 C (66.0 F) |
| 2021-08-02 | Record high minimum temperature | Record high minimum temperature 21.1 C (70.0 F) |
Wettest Day of Each Month
May: 51.3 mm (2.0 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 35.6 mm (1.4 in) | 10 January 2006 |
| Feb | 27.9 mm (1.1 in) | 16 February 2017 |
| Mar | 34.3 mm (1.4 in) | 23 March 1967 |
| Apr | 38.4 mm (1.5 in) | 11 April 2023 |
| May | 51.3 mm (2.0 in) | 27 May 1998 |
| Jun | 48.8 mm (1.9 in) | 20 June 2013 |
| Jul | 51.1 mm (2.0 in) | 21 July 1997 |
| Aug | 42.7 mm (1.7 in) | 24 August 1983 |
| Sep | 38.4 mm (1.5 in) | 29 September 2013 |
| Oct | 46.2 mm (1.8 in) | 14 October 2016 |
| Nov | 37.1 mm (1.5 in) | 4 November 1983 |
| Dec | 45.0 mm (1.8 in) | 15 December 2002 |
Period of Record Coverage
1965 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1965 | 181 | 50% | No |
| 1966 | 359 | 98% | Yes |
| 1967 | 364 | 100% | Yes |
| 1968 | 356 | 97% | Yes |
| 1969 | 359 | 98% | Yes |
| 1970 | 334 | 92% | Yes |
| 1974 | 266 | 73% | No |
| 1975 | 312 | 85% | No |
| 1976 | 360 | 98% | Yes |
| 1977 | 359 | 98% | Yes |
| 1978 | 331 | 91% | Yes |
| 1979 | 349 | 96% | Yes |
| 1980 | 365 | 100% | Yes |
| 1981 | 363 | 99% | Yes |
| 1982 | 359 | 98% | Yes |
| 1983 | 352 | 96% | Yes |
| 1984 | 363 | 99% | Yes |
| 1985 | 358 | 98% | Yes |
| 1986 | 364 | 100% | Yes |
| 1987 | 365 | 100% | Yes |
| 1988 | 360 | 98% | Yes |
| 1989 | 363 | 99% | Yes |
| 1990 | 365 | 100% | Yes |
| 1991 | 364 | 100% | Yes |
| 1992 | 366 | 100% | Yes |
| 1993 | 365 | 100% | Yes |
| 1994 | 364 | 100% | Yes |
| 1995 | 363 | 99% | Yes |
| 1996 | 365 | 100% | Yes |
| 1997 | 364 | 100% | Yes |
| 1998 | 364 | 100% | Yes |
| 1999 | 365 | 100% | Yes |
| 2000 | 363 | 99% | Yes |
| 2001 | 363 | 99% | Yes |
| 2002 | 364 | 100% | Yes |
| 2003 | 362 | 99% | Yes |
| 2004 | 361 | 99% | Yes |
| 2005 | 364 | 100% | Yes |
| 2006 | 357 | 98% | Yes |
| 2007 | 362 | 99% | Yes |
| 2008 | 363 | 99% | Yes |
| 2009 | 329 | 90% | Yes |
| 2010 | 365 | 100% | Yes |
| 2011 | 365 | 100% | Yes |
| 2012 | 360 | 98% | Yes |
| 2013 | 362 | 99% | Yes |
| 2014 | 357 | 98% | Yes |
| 2015 | 361 | 99% | Yes |
| 2016 | 356 | 97% | Yes |
| 2017 | 362 | 99% | Yes |
| 2018 | 353 | 97% | Yes |
| 2019 | 343 | 94% | Yes |
| 2020 | 352 | 96% | Yes |
| 2021 | 333 | 91% | Yes |
| 2022 | 353 | 97% | Yes |
| 2023 | 343 | 94% | Yes |
| 2024 | 347 | 95% | Yes |
| 2025 | 361 | 99% | Yes |
| 2026 | 273 | 75% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 8 September 2026 | Boundary Dam, US | daily low max (Tie, Provisional) | 16.1 C (61.0 F) | tie | 16 years | 2 of 100 (Routine) |
| 27 August 2026 | Boundary Dam, US | daily high max (Provisional) | 35.0 C (95.0 F) | 1.1 C (2.0 F) | 16 years | 12 of 100 (Routine) |
| 23 August 2026 | Boundary Dam, US | daily high max (Provisional) | 35.6 C (96.1 F) | 0.6 C (1.1 F) | 56 years | 23 of 100 (Routine) |
| 22 August 2026 | Boundary Dam, US | daily high max (Provisional) | 37.2 C (99.0 F) | 1.1 C (2.0 F) | 20 years | 14 of 100 (Routine) |
| 3 August 2026 | Boundary Dam, US | daily low min | 4.4 C (39.9 F) | 0.6 C (1.1 F) | 24 years | 15 of 100 (Routine) |
| 6 July 2026 | Boundary Dam, US | daily low min (Tie) | 5.6 C (42.1 F) | tie | 36 years | 4 of 100 (Routine) |
| 1 July 2026 | Boundary Dam, US | daily low max | 14.4 C (57.9 F) | 2.3 C (4.1 F) | 43 years | 22 of 100 (Routine) |
| 29 May 2026 | Boundary Dam, US | daily high max | 34.4 C (93.9 F) | 1.1 C (2.0 F) | 0 years | 8 of 100 (Routine) |
| 21 May 2026 | Boundary Dam, US | daily low min (Tie) | 0.6 C (33.1 F) | tie | 4 years | 1 of 100 (Routine) |
| 17 May 2026 | Boundary Dam, US | daily rain | 6.4 mm (0.25 in) | 0.8 mm (0.03 in) | 1 year | 7 of 100 (Routine) |
| 25 April 2026 | Boundary Dam, US | daily low min | -6.7 C (19.9 F) | 1.7 C (3.1 F) | 41 years | 23 of 100 (Routine) |
| 12 April 2026 | Boundary Dam, US | daily high min | 4.4 C (39.9 F) | 1.1 C (2.0 F) | 49 years | 23 of 100 (Routine) |
| 7 April 2026 | Boundary Dam, US | daily high max (Tie) | 22.8 C (73.0 F) | tie | 48 years | 5 of 100 (Routine) |
| 6 April 2026 | Boundary Dam, US | daily low min | -5.6 C (21.9 F) | 0.6 C (1.1 F) | 17 years | 13 of 100 (Routine) |
| 21 March 2026 | Boundary Dam, US | daily high max | 17.8 C (64.0 F) | 1.1 C (2.0 F) | 27 years | 16 of 100 (Routine) |
| 20 March 2026 | Boundary Dam, US | daily high min | 4.4 C (39.9 F) | 2.7 C (4.9 F) | 36 years | 23 of 100 (Routine) |
| 19 March 2026 | Boundary Dam, US | daily high min | 3.3 C (37.9 F) | 1.1 C (2.0 F) | 41 years | 21 of 100 (Routine) |
| 17 March 2026 | Boundary Dam, US | daily low max (Tie) | 3.9 C (39.0 F) | tie | 24 years | 3 of 100 (Routine) |
| 16 March 2026 | Boundary Dam, US | daily snowfall (Tie) | 5.1 cm (2.0 in) | tie | 28 years | 3 of 100 (Routine) |
| 9 March 2026 | Boundary Dam, US | daily high max | 17.8 C (64.0 F) | 1.1 C (2.0 F) | 11 years | 11 of 100 (Routine) |
Climate Trend
51 complete years, 1966 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1966 | 8.2 C | +0.75 C |
| 1967 | 8.3 C | +0.81 C |
| 1968 | 6.8 C | -0.67 C |
| 1969 | 6.7 C | -0.76 C |
| 1976 | 6.6 C | -0.85 C |
| 1977 | 6.8 C | -0.66 C |
| 1979 | 6.8 C | -0.73 C |
| 1980 | 7.2 C | -0.34 C |
| 1981 | 7.7 C | +0.18 C |
| 1982 | 6.3 C | -1.17 C |
| 1984 | 6.0 C | -1.46 C |
| 1985 | 5.7 C | -1.84 C |
| 1986 | 7.5 C | -0.01 C |
| 1987 | 8.6 C | +1.09 C |
| 1988 | 8.1 C | +0.58 C |
| 1989 | 7.5 C | 0.00 C |
| 1990 | 7.7 C | +0.16 C |
| 1991 | 7.4 C | -0.13 C |
| 1992 | 8.7 C | +1.16 C |
| 1993 | 6.6 C | -0.91 C |
| 1994 | 8.2 C | +0.68 C |
| 1995 | 7.5 C | -0.01 C |
| 1996 | 6.3 C | -1.15 C |
| 1997 | 7.2 C | -0.30 C |
| 1998 | 9.0 C | +1.48 C |
| 1999 | 7.6 C | +0.13 C |
| 2000 | 7.1 C | -0.39 C |
| 2001 | 7.8 C | +0.30 C |
| 2002 | 7.2 C | -0.29 C |
| 2003 | 8.0 C | +0.54 C |
| 2004 | 8.2 C | +0.70 C |
| 2005 | 6.9 C | -0.63 C |
| 2006 | 7.5 C | +0.01 C |
| 2007 | 6.7 C | -0.77 C |
| 2008 | 5.3 C | -2.16 C |
| 2010 | 7.9 C | +0.44 C |
| 2011 | 6.8 C | -0.66 C |
| 2012 | 7.8 C | +0.26 C |
| 2013 | 7.7 C | +0.21 C |
| 2014 | 7.3 C | -0.23 C |
| 2015 | 9.2 C | +1.67 C |
| 2016 | 8.9 C | +1.45 C |
| 2017 | 7.5 C | -0.01 C |
| 2018 | 7.8 C | +0.27 C |
| 2019 | 7.5 C | -0.01 C |
| 2020 | 7.9 C | +0.40 C |
| 2021 | 8.5 C | +0.98 C |
| 2022 | 7.2 C | -0.26 C |
| 2023 | 8.4 C | +0.95 C |
| 2024 | 8.2 C | +0.74 C |
| 2025 | 8.1 C | +0.64 C |
The annual mean temperature here has risen by 0.15 C (0.01 to 0.28) per decade over 1966 to 2025. In Fahrenheit: 0.27 F (0.02 to 0.51) per decade. The slope is a straight line fitted to 51 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.15 C (0.01 to 0.28) per decade | 0.27 F (0.02 to 0.51) per decade | 1966 to 2025 | 51 | Rise |
| Mean daily maximum | 0.2 C (0.1 to 0.4) per decade | 0.4 F (0.2 to 0.7) per decade | 1966 to 2025 | 51 | Rise |
| Mean daily minimum | 0.1 C (-0.1 to 0.2) per decade | 0.1 F (-0.2 to 0.4) per decade | 1966 to 2025 | 51 | 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
1965 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 43.9 C (111.0 F) | 2021 | 37.2 C (99.0 F) | 59 |
| Coldest night (TNn) | -33.3 C (-27.9 F) | 1968 | -21.1 C (-6.0 F) | 59 |
| Wettest day (Rx1day) | 51.3 mm (2.0 in) | 1998 | 29.2 mm (1.1 in) | 59 |
| Wettest five days (Rx5day) | 97.0 mm (3.8 in) | 2002 | 54.4 mm (2.1 in) | 59 |
| Longest dry spell (CDD) | 55 days | 1994 | 24 days | 59 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1965 | 37.8 C (100.0 F) |
| 1966 | 35.6 C (96.1 F) |
| 1967 | 37.2 C (99.0 F) |
| 1968 | 36.1 C (97.0 F) |
| 1969 | 35.6 C (96.1 F) |
| 1970 | 36.7 C (98.1 F) |
| 1974 | 35.0 C (95.0 F) |
| 1975 | 35.6 C (96.1 F) |
| 1976 | 30.0 C (86.0 F) |
| 1977 | 37.2 C (99.0 F) |
| 1978 | 36.7 C (98.1 F) |
| 1979 | 38.9 C (102.0 F) |
| 1980 | 36.1 C (97.0 F) |
| 1981 | 36.7 C (98.1 F) |
| 1982 | 35.6 C (96.1 F) |
| 1983 | 35.6 C (96.1 F) |
| 1984 | 38.3 C (100.9 F) |
| 1985 | 39.4 C (102.9 F) |
| 1986 | 36.7 C (98.1 F) |
| 1987 | 36.1 C (97.0 F) |
| 1988 | 38.3 C (100.9 F) |
| 1989 | 37.2 C (99.0 F) |
| 1990 | 37.2 C (99.0 F) |
| 1991 | 37.2 C (99.0 F) |
| 1992 | 37.2 C (99.0 F) |
| 1993 | 35.6 C (96.1 F) |
| 1994 | 40.0 C (104.0 F) |
| 1995 | 35.0 C (95.0 F) |
| 1996 | 37.2 C (99.0 F) |
| 1997 | 35.6 C (96.1 F) |
| 1998 | 38.3 C (100.9 F) |
| 1999 | 36.7 C (98.1 F) |
| 2000 | 36.7 C (98.1 F) |
| 2001 | 37.8 C (100.0 F) |
| 2002 | 37.8 C (100.0 F) |
| 2003 | 39.4 C (102.9 F) |
| 2004 | 38.9 C (102.0 F) |
| 2005 | 35.0 C (95.0 F) |
| 2006 | 38.3 C (100.9 F) |
| 2007 | 40.0 C (104.0 F) |
| 2008 | 38.9 C (102.0 F) |
| 2009 | 36.7 C (98.1 F) |
| 2010 | 35.0 C (95.0 F) |
| 2011 | 34.4 C (93.9 F) |
| 2012 | 36.7 C (98.1 F) |
| 2013 | 36.1 C (97.0 F) |
| 2014 | 37.2 C (99.0 F) |
| 2015 | 40.6 C (105.1 F) |
| 2016 | 36.7 C (98.1 F) |
| 2017 | 37.2 C (99.0 F) |
| 2018 | 37.8 C (100.0 F) |
| 2019 | 36.7 C (98.1 F) |
| 2020 | 40.0 C (104.0 F) |
| 2021 | 43.9 C (111.0 F) |
| 2022 | 38.9 C (102.0 F) |
| 2023 | 39.4 C (102.9 F) |
| 2024 | 40.6 C (105.1 F) |
| 2025 | 37.8 C (100.0 F) |
| 2026 | 37.2 C (99.0 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1965 | -15.6 C (3.9 F) |
| 1966 | -18.9 C (-2.0 F) |
| 1967 | -17.8 C (0.0 F) |
| 1968 | -33.3 C (-27.9 F) |
| 1969 | -26.1 C (-15.0 F) |
| 1970 | -21.1 C (-6.0 F) |
| 1974 | -12.8 C (9.0 F) |
| 1975 | -23.9 C (-11.0 F) |
| 1976 | -19.4 C (-2.9 F) |
| 1977 | -19.4 C (-2.9 F) |
| 1978 | -28.9 C (-20.0 F) |
| 1979 | -28.9 C (-20.0 F) |
| 1980 | -26.1 C (-15.0 F) |
| 1981 | -16.7 C (1.9 F) |
| 1982 | -24.4 C (-11.9 F) |
| 1983 | -26.7 C (-16.1 F) |
| 1984 | -25.0 C (-13.0 F) |
| 1985 | -28.3 C (-18.9 F) |
| 1986 | -18.9 C (-2.0 F) |
| 1987 | -21.7 C (-7.1 F) |
| 1988 | -20.0 C (-4.0 F) |
| 1989 | -22.8 C (-9.0 F) |
| 1990 | -30.6 C (-23.1 F) |
| 1991 | -21.1 C (-6.0 F) |
| 1992 | -17.8 C (0.0 F) |
| 1993 | -24.4 C (-11.9 F) |
| 1994 | -20.0 C (-4.0 F) |
| 1995 | -19.4 C (-2.9 F) |
| 1996 | -25.0 C (-13.0 F) |
| 1997 | -20.6 C (-5.1 F) |
| 1998 | -23.3 C (-9.9 F) |
| 1999 | -12.8 C (9.0 F) |
| 2000 | -17.8 C (0.0 F) |
| 2001 | -16.1 C (3.0 F) |
| 2002 | -14.4 C (6.1 F) |
| 2003 | -17.2 C (1.0 F) |
| 2004 | -27.2 C (-17.0 F) |
| 2005 | -25.0 C (-13.0 F) |
| 2006 | -21.7 C (-7.1 F) |
| 2007 | -24.4 C (-11.9 F) |
| 2008 | -22.8 C (-9.0 F) |
| 2009 | -20.6 C (-5.1 F) |
| 2010 | -17.8 C (0.0 F) |
| 2011 | -22.2 C (-8.0 F) |
| 2012 | -14.4 C (6.1 F) |
| 2013 | -21.7 C (-7.1 F) |
| 2014 | -26.1 C (-15.0 F) |
| 2015 | -16.7 C (1.9 F) |
| 2016 | -20.0 C (-4.0 F) |
| 2017 | -22.8 C (-9.0 F) |
| 2018 | -18.9 C (-2.0 F) |
| 2019 | -20.6 C (-5.1 F) |
| 2020 | -12.8 C (9.0 F) |
| 2021 | -20.6 C (-5.1 F) |
| 2022 | -28.9 C (-20.0 F) |
| 2023 | -18.9 C (-2.0 F) |
| 2024 | -28.9 C (-20.0 F) |
| 2025 | -21.1 C (-6.0 F) |
| 2026 | -14.4 C (6.1 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1965 | 20.8 mm (0.8 in) |
| 1966 | 35.3 mm (1.4 in) |
| 1967 | 34.3 mm (1.4 in) |
| 1968 | 25.7 mm (1.0 in) |
| 1969 | 26.9 mm (1.1 in) |
| 1970 | 23.9 mm (0.9 in) |
| 1974 | 28.4 mm (1.1 in) |
| 1975 | 32.5 mm (1.3 in) |
| 1976 | 37.1 mm (1.5 in) |
| 1977 | 31.0 mm (1.2 in) |
| 1978 | 26.9 mm (1.1 in) |
| 1979 | 25.4 mm (1.0 in) |
| 1980 | 40.1 mm (1.6 in) |
| 1981 | 26.2 mm (1.0 in) |
| 1982 | 24.9 mm (1.0 in) |
| 1983 | 42.7 mm (1.7 in) |
| 1984 | 35.8 mm (1.4 in) |
| 1985 | 24.6 mm (1.0 in) |
| 1986 | 26.7 mm (1.1 in) |
| 1987 | 25.7 mm (1.0 in) |
| 1988 | 34.3 mm (1.4 in) |
| 1989 | 22.4 mm (0.9 in) |
| 1990 | 29.0 mm (1.1 in) |
| 1991 | 27.2 mm (1.1 in) |
| 1992 | 40.6 mm (1.6 in) |
| 1993 | 26.7 mm (1.1 in) |
| 1994 | 29.2 mm (1.1 in) |
| 1995 | 37.3 mm (1.5 in) |
| 1996 | 36.8 mm (1.4 in) |
| 1997 | 51.1 mm (2.0 in) |
| 1998 | 51.3 mm (2.0 in) |
| 1999 | 37.3 mm (1.5 in) |
| 2000 | 20.8 mm (0.8 in) |
| 2001 | 30.0 mm (1.2 in) |
| 2002 | 45.0 mm (1.8 in) |
| 2003 | 23.9 mm (0.9 in) |
| 2004 | 35.6 mm (1.4 in) |
| 2005 | 24.9 mm (1.0 in) |
| 2006 | 39.9 mm (1.6 in) |
| 2007 | 34.3 mm (1.4 in) |
| 2008 | 20.8 mm (0.8 in) |
| 2009 | 20.6 mm (0.8 in) |
| 2010 | 20.3 mm (0.8 in) |
| 2011 | 33.0 mm (1.3 in) |
| 2012 | 29.5 mm (1.2 in) |
| 2013 | 50.5 mm (2.0 in) |
| 2014 | 28.2 mm (1.1 in) |
| 2015 | 29.2 mm (1.1 in) |
| 2016 | 46.2 mm (1.8 in) |
| 2017 | 27.9 mm (1.1 in) |
| 2018 | 29.2 mm (1.1 in) |
| 2019 | 19.1 mm (0.8 in) |
| 2020 | 30.5 mm (1.2 in) |
| 2021 | 45.7 mm (1.8 in) |
| 2022 | 33.0 mm (1.3 in) |
| 2023 | 38.4 mm (1.5 in) |
| 2024 | 25.4 mm (1.0 in) |
| 2025 | 27.9 mm (1.1 in) |
| 2026 | 16.5 mm (0.6 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1965 | 27.7 mm (1.1 in) |
| 1966 | 68.1 mm (2.7 in) |
| 1967 | 42.0 mm (1.7 in) |
| 1968 | 46.5 mm (1.8 in) |
| 1969 | 65.0 mm (2.6 in) |
| 1970 | 42.9 mm (1.7 in) |
| 1974 | 64.2 mm (2.5 in) |
| 1975 | 51.1 mm (2.0 in) |
| 1976 | 55.0 mm (2.2 in) |
| 1977 | 42.0 mm (1.7 in) |
| 1978 | 52.0 mm (2.0 in) |
| 1979 | 53.6 mm (2.1 in) |
| 1980 | 45.3 mm (1.8 in) |
| 1981 | 42.9 mm (1.7 in) |
| 1982 | 61.3 mm (2.4 in) |
| 1983 | 84.4 mm (3.3 in) |
| 1984 | 51.4 mm (2.0 in) |
| 1985 | 41.1 mm (1.6 in) |
| 1986 | 50.3 mm (2.0 in) |
| 1987 | 50.9 mm (2.0 in) |
| 1988 | 58.9 mm (2.3 in) |
| 1989 | 40.9 mm (1.6 in) |
| 1990 | 63.8 mm (2.5 in) |
| 1991 | 40.7 mm (1.6 in) |
| 1992 | 54.4 mm (2.1 in) |
| 1993 | 47.6 mm (1.9 in) |
| 1994 | 58.1 mm (2.3 in) |
| 1995 | 71.5 mm (2.8 in) |
| 1996 | 61.8 mm (2.4 in) |
| 1997 | 79.3 mm (3.1 in) |
| 1998 | 95.0 mm (3.7 in) |
| 1999 | 57.9 mm (2.3 in) |
| 2000 | 44.4 mm (1.7 in) |
| 2001 | 72.7 mm (2.9 in) |
| 2002 | 97.0 mm (3.8 in) |
| 2003 | 52.6 mm (2.1 in) |
| 2004 | 59.7 mm (2.4 in) |
| 2005 | 64.8 mm (2.6 in) |
| 2006 | 74.5 mm (2.9 in) |
| 2007 | 41.9 mm (1.6 in) |
| 2008 | 35.1 mm (1.4 in) |
| 2009 | 52.4 mm (2.1 in) |
| 2010 | 37.3 mm (1.5 in) |
| 2011 | 67.1 mm (2.6 in) |
| 2012 | 87.4 mm (3.4 in) |
| 2013 | 90.7 mm (3.6 in) |
| 2014 | 49.3 mm (1.9 in) |
| 2015 | 62.7 mm (2.5 in) |
| 2016 | 80.0 mm (3.1 in) |
| 2017 | 60.3 mm (2.4 in) |
| 2018 | 51.6 mm (2.0 in) |
| 2019 | 30.5 mm (1.2 in) |
| 2020 | 55.2 mm (2.2 in) |
| 2021 | 49.6 mm (2.0 in) |
| 2022 | 76.4 mm (3.0 in) |
| 2023 | 59.8 mm (2.4 in) |
| 2024 | 56.9 mm (2.2 in) |
| 2025 | 45.8 mm (1.8 in) |
| 2026 | 28.2 mm (1.1 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1965 | 17 days |
| 1966 | 21 days |
| 1967 | 46 days |
| 1968 | 24 days |
| 1969 | 49 days |
| 1970 | 31 days |
| 1974 | 51 days |
| 1975 | 16 days |
| 1976 | 24 days |
| 1977 | 25 days |
| 1978 | 16 days |
| 1979 | 35 days |
| 1980 | 14 days |
| 1981 | 15 days |
| 1982 | 15 days |
| 1983 | 30 days |
| 1984 | 29 days |
| 1985 | 40 days |
| 1986 | 33 days |
| 1987 | 22 days |
| 1988 | 30 days |
| 1989 | 25 days |
| 1990 | 31 days |
| 1991 | 37 days |
| 1992 | 27 days |
| 1993 | 21 days |
| 1994 | 55 days |
| 1995 | 21 days |
| 1996 | 33 days |
| 1997 | 18 days |
| 1998 | 21 days |
| 1999 | 17 days |
| 2000 | 40 days |
| 2001 | 22 days |
| 2002 | 27 days |
| 2003 | 54 days |
| 2004 | 19 days |
| 2005 | 48 days |
| 2006 | 40 days |
| 2007 | 31 days |
| 2008 | 19 days |
| 2009 | 22 days |
| 2010 | 17 days |
| 2011 | 19 days |
| 2012 | 25 days |
| 2013 | 19 days |
| 2014 | 19 days |
| 2015 | 39 days |
| 2016 | 22 days |
| 2017 | 34 days |
| 2018 | 28 days |
| 2019 | 14 days |
| 2020 | 23 days |
| 2021 | 22 days |
| 2022 | 36 days |
| 2023 | 21 days |
| 2024 | 17 days |
| 2025 | 26 days |
| 2026 | 23 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
51 years with a frostAcross 51 years with a frost, the median last spring frost at Boundary Dam falls on 8 May and the median first autumn frost on 3 October, which leaves a median of 143 days between them.
Fitted over all years, the growing season changes by -0.3 days per decade at this station.
| Measure | Median, all years | Earliest period | Recent period (1995 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 8 May | n/a | 10 May | n/a | +0.2 days per decade |
| First autumn frost | 3 October | n/a | 2 October | n/a | -0.1 days per decade |
| Growing days | 143 days | n/a | 143 days | n/a | -0.3 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
55 years, 1966 to 2025A day with at least 30.3 mm (1.2 in) of rain is expected about once in 2 years. A day with at least 58.9 mm (2.3 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 30.3 mm (1.2 in) | |
| 5 years | 37.8 mm (1.5 in) | |
| 10 years | 42.9 mm (1.7 in) | |
| 25 years | 49.3 mm (1.9 in) | |
| 50 years | 54.1 mm (2.1 in) | |
| 100 years | 58.9 mm (2.3 in) | Longer than the 55 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, 55 years of values from 1966 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: 51.3 mm (2.0 in) in 1998; 51.1 mm (2.0 in) in 1997; 50.5 mm (2.0 in) in 2013.
Station Changes
1 suspectedOne change was suspected in the annual mean temperature of Boundary Dam, at 2002. Each is measured against neighbouring stations.
- Relative to 5 neighbouring stations, the station's annual mean temperature from 2002 ran 0.3 C (0.5 F) lower than in the years before (possible change).
| Year | Shift (C) | Shift (F) | Strength | Neighbours |
|---|---|---|---|---|
| 2002 | -0.3 | -0.5 | possible | 5 |
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
Climate Twins
2011 to 2025 against 1961 to 1990Over 2011 to 2025, Boundary Dam had a mean temperature of 7.9 C (46.3 F) and 693.8 mm (27.3 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Mtn Dell Dam (United States, 1,018 km away), Troy (United States, 121 km away) and Cabinet Gorge (United States, 139 km away).
| Twin station | Country | Distance away | Mean temperature, 1961-1990 | Rain a year, 1961-1990 | Climate difference |
|---|---|---|---|---|---|
| Mtn Dell Dam | United States | 1,018 km (633 mi) | 8.1 C (46.7 F) | 612.7 mm (24.1 in) | 0.78 |
| Troy | United States | 121 km (75 mi) | 7.6 C (45.6 F) | 610.8 mm (24.0 in) | 1.01 |
| Cabinet Gorge | United States | 139 km (86 mi) | 7.9 C (46.1 F) | 811.4 mm (31.9 in) | 1.04 |
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).