Frost history / N Willamette Exp Stn, OR
N Willamette Exp Stn, OR: frost dates by year
Last spring and first fall frost at NOAA station USC00356151, 1963 to 2007, measured from daily minimum temperatures.
Elevation 150 ft, 45.282, -122.752. Download the data (JSON) · NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Apr 15 | Oct 30 |
| Earliest | Mar 1 (1993) | Sep 24 (1970) |
| Latest | May 20 (1975) | Dec 4 (1999) |
| Trend | 5.5 days earlier per decade | 3.9 days later per decade |
| Years with data | 43 | 41 |
At 28°F (hard freeze) the median last spring date is Mar 12 and the median first fall date is Nov 20.
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 |
|---|---|---|---|---|
| 2007 | Apr 20 | no data | Feb 3 | no data |
| 2006 | Mar 20 | Oct 30 | Mar 13 | Nov 1 |
| 2005 | Mar 17 | Nov 7 | Feb 17 | Nov 22 |
| 2004 | Mar 31 | Nov 5 | Feb 13 | Nov 28 |
| 2003 | Mar 24 | Nov 1 | Feb 26 | Nov 1 |
| 2001 | Apr 25 | no data | Apr 21 | no data |
| 2000 | Apr 24 | no data | Jan 29 | no data |
| 1999 | Apr 2 | Dec 4 | none | Dec 24 |
| 1998 | Apr 1 | Dec 2 | Mar 30 | Dec 4 |
| 1997 | Apr 12 | Oct 25 | Apr 4 | Dec 11 |
| 1996 | May 8 | Nov 1 | Mar 26 | Nov 23 |
| 1995 | Apr 22 | Oct 31 | Mar 27 | Nov 2 |
| 1994 | Mar 13 | Oct 18 | Feb 9 | Nov 18 |
| 1993 | Mar 1 | Nov 1 | Feb 28 | Nov 6 |
| 1992 | Apr 23 | Oct 14 | Feb 6 | Nov 24 |
| 1991 | Apr 13 | Oct 31 | Jan 31 | Nov 30 |
| 1990 | Apr 9 | Oct 7 | Mar 13 | Dec 19 |
| 1989 | Apr 3 | Oct 29 | Mar 4 | Nov 2 |
| 1988 | Apr 8 | Nov 30 | Mar 12 | Dec 4 |
| 1987 | Mar 30 | Nov 18 | Feb 25 | Nov 29 |
| 1986 | Apr 24 | Nov 10 | Feb 10 | Dec 3 |
| 1985 | May 12 | Oct 9 | Mar 14 | Nov 11 |
| 1984 | Apr 27 | Nov 17 | Feb 2 | Dec 6 |
| 1983 | Apr 14 | Oct 16 | Feb 4 | Dec 20 |
| 1982 | Apr 29 | Oct 19 | Feb 11 | Nov 9 |
| 1981 | Mar 19 | Oct 13 | Mar 16 | Nov 28 |
| 1980 | Apr 7 | Oct 23 | Feb 13 | Nov 13 |
| 1979 | Mar 21 | Nov 8 | Feb 3 | Nov 14 |
| 1978 | May 5 | Oct 22 | Feb 12 | Nov 11 |
| 1977 | May 12 | Nov 4 | Apr 17 | Nov 8 |
| 1976 | Apr 23 | Oct 19 | Mar 12 | Nov 13 |
| 1975 | May 20 | Nov 8 | Apr 6 | Nov 12 |
| 1974 | Mar 24 | Oct 5 | Mar 9 | Dec 23 |
| 1973 | Apr 29 | Nov 2 | Feb 19 | Nov 3 |
| 1972 | Apr 22 | Sep 27 | Mar 29 | Nov 27 |
| 1971 | Apr 12 | Oct 16 | Mar 17 | Oct 28 |
| 1970 | Apr 15 | Sep 24 | Mar 31 | Oct 28 |
| 1969 | Apr 30 | Oct 18 | Mar 14 | Nov 27 |
| 1968 | Apr 24 | Oct 31 | Apr 13 | Nov 4 |
| 1967 | Apr 29 | Nov 23 | Apr 19 | Nov 26 |
| 1966 | Mar 22 | Oct 13 | Mar 22 | Oct 18 |
| 1965 | May 8 | Nov 26 | Apr 3 | Nov 29 |
| 1964 | May 3 | Oct 21 | Apr 17 | Nov 15 |
| 1963 | no data | Oct 19 | no data | Nov 20 |
"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 1991–2020 frost probabilities.