Frost history / Chief Joseph Dam, WA
Chief Joseph Dam, WA: frost dates by year
Last spring and first fall frost at NOAA station USC00451400, 1951 to 2020, measured from daily minimum temperatures.
Elevation 834 ft, 47.997, -119.648. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Apr 22 | Oct 13 |
| Earliest | Mar 26 (1969) | Sep 19 (1971) |
| Latest | Jul 9 (2011) | Nov 10 (2014) |
| Trend | 1.0 days later per decade | little change (less than half a day per decade) |
| Years with data | 62 | 62 |
At 28°F (hard freeze) the median last spring date is Apr 6 and the median first fall date is Oct 25.
The trend is a straight-line fit through the years with a freeze. A positive spring trend means the last frost now comes later. Short or patchy records give noisy trends.
Chart
Last spring frost (32°F)
First fall frost (32°F)
Dots are single years. The gray line is the median, the green line the fitted trend.
Year by year
| Year | Last spring 32°F | First fall 32°F | Last spring 28°F | First fall 28°F |
|---|---|---|---|---|
| 2020 | May 4 | no data | Apr 13 | no data |
| 2019 | Apr 2 | Oct 10 | Mar 27 | Oct 10 |
| 2018 | Apr 3 | no data | Mar 12 | no data |
| 2017 | Apr 16 | no data | Mar 20 | no data |
| 2016 | Apr 5 | Oct 11 | Mar 19 | Oct 12 |
| 2015 | Apr 28 | no data | Apr 17 | no data |
| 2014 | Apr 20 | Nov 10 | Mar 23 | Nov 11 |
| 2013 | May 26 | Oct 4 | May 25 | Oct 31 |
| 2012 | May 11 | Oct 4 | Apr 8 | Oct 22 |
| 2011 | Jul 9 | Oct 24 | Apr 20 | Oct 25 |
| 2010 | Jun 17 | Oct 16 | Jun 17 | Oct 17 |
| 2009 | Apr 24 | Oct 6 | Apr 3 | Oct 10 |
| 2008 | no data | Oct 11 | no data | Oct 27 |
| 2007 | Apr 20 | Oct 17 | Apr 20 | Oct 26 |
| 2006 | Apr 18 | Oct 9 | Apr 17 | Oct 30 |
| 2005 | Apr 15 | Oct 4 | Mar 23 | Nov 8 |
| 2004 | Mar 29 | Oct 24 | Mar 20 | Oct 25 |
| 2003 | May 7 | Oct 10 | Apr 5 | Oct 30 |
| 2002 | May 8 | Oct 2 | Apr 24 | Oct 12 |
| 2001 | Apr 19 | Oct 5 | Apr 14 | Oct 28 |
| 2000 | May 13 | Sep 23 | Apr 7 | Oct 6 |
| 1999 | May 10 | Sep 28 | May 10 | Oct 16 |
| 1998 | Apr 14 | Oct 10 | Mar 28 | Oct 18 |
| 1996 | May 8 | Oct 16 | May 3 | Oct 17 |
| 1995 | Apr 16 | Oct 19 | Apr 15 | Oct 28 |
| 1994 | May 5 | Oct 22 | May 5 | Oct 29 |
| 1993 | Apr 13 | Oct 20 | Mar 19 | Nov 1 |
| 1992 | Apr 23 | Oct 14 | Apr 8 | Oct 14 |
| 1991 | no data | Oct 17 | no data | Oct 23 |
| 1990 | Mar 27 | no data | Mar 26 | no data |
| 1989 | Apr 9 | Oct 16 | Apr 3 | Oct 16 |
| 1988 | Apr 25 | Oct 27 | Apr 9 | Oct 27 |
| 1987 | Mar 30 | Oct 10 | Mar 30 | Nov 17 |
| 1986 | Apr 30 | Oct 12 | Mar 5 | Nov 8 |
| 1985 | May 12 | Sep 29 | Apr 21 | Oct 8 |
| 1984 | Mar 31 | Sep 28 | Mar 2 | Oct 18 |
| 1983 | Apr 15 | Sep 28 | Apr 11 | Nov 26 |
| 1982 | Apr 30 | Oct 19 | Apr 19 | Oct 19 |
| 1981 | May 5 | Oct 3 | Apr 14 | Nov 5 |
| 1980 | Apr 7 | Oct 22 | Mar 26 | Oct 23 |
| 1979 | Apr 21 | Nov 1 | Apr 20 | Nov 19 |
| 1978 | Apr 12 | Oct 13 | Mar 16 | Oct 25 |
| 1977 | no data | Oct 4 | no data | Nov 3 |
| 1976 | Apr 23 | Oct 15 | Mar 8 | Oct 19 |
| 1975 | Apr 21 | Oct 7 | Apr 5 | Oct 25 |
| 1974 | May 16 | Sep 26 | Mar 21 | Nov 22 |
| 1972 | no data | Sep 27 | no data | Oct 30 |
| 1971 | Apr 16 | Sep 19 | Mar 20 | Oct 2 |
| 1970 | Apr 27 | Oct 7 | Apr 25 | Oct 14 |
| 1969 | Mar 26 | Oct 13 | Mar 15 | Oct 13 |
| 1968 | May 5 | Oct 3 | May 5 | Oct 7 |
| 1967 | Apr 26 | Oct 26 | Apr 15 | Nov 4 |
| 1966 | Apr 19 | Oct 16 | Mar 22 | Oct 16 |
| 1965 | Apr 7 | Oct 7 | Mar 28 | Nov 25 |
| 1964 | no data | Oct 16 | no data | Oct 26 |
| 1963 | May 4 | Oct 19 | Mar 29 | Oct 19 |
| 1962 | Apr 8 | Nov 7 | Mar 15 | Nov 23 |
| 1961 | Apr 21 | Oct 18 | Apr 20 | Oct 22 |
| 1960 | Apr 23 | Oct 13 | Mar 13 | Oct 29 |
| 1959 | May 12 | Oct 1 | Mar 20 | Nov 5 |
| 1958 | Apr 6 | Sep 24 | Mar 17 | Oct 24 |
| 1957 | Apr 16 | Nov 3 | Mar 28 | Nov 8 |
| 1956 | no data | Oct 22 | no data | Nov 2 |
| 1955 | May 20 | Oct 23 | Apr 28 | Oct 23 |
| 1954 | May 1 | no data | May 1 | no data |
| 1953 | Apr 15 | Oct 2 | Apr 15 | Nov 3 |
| 1952 | May 5 | Oct 14 | Apr 10 | Oct 26 |
| 1951 | Apr 25 | Oct 26 | Apr 20 | Oct 26 |
"none" means the station recorded no freeze at that threshold in that half of the year. "no data" means more than 10% of the season's daily readings were missing. Years with no usable data are left out. See the methodology for the rules, and the ZIP lookup for 1991 to 2020 frost probabilities.