Frost history / Port Alsworth, AK
Port Alsworth, AK: frost dates by year
Last spring and first fall frost at NOAA station USC00507570, 1960 to 2020, measured from daily minimum temperatures.
Elevation 260 ft, 60.204, -154.316. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 27 | Sep 5 |
| Earliest | Apr 28 (2004) | Aug 3 (1961) |
| Latest | Jul 31 (1974) | Oct 15 (2020) |
| Trend | 8.9 days earlier per decade | 6.0 days later per decade |
| Years with data | 53 | 48 |
At 28°F (hard freeze) the median last spring date is May 13 and the median first fall date is Sep 23.
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 27 | Oct 15 | Apr 29 | Oct 16 |
| 2014 | Apr 30 | no data | Apr 29 | no data |
| 2013 | Jun 6 | no data | May 19 | no data |
| 2012 | no data | Sep 10 | no data | Sep 29 |
| 2011 | May 22 | Sep 28 | May 13 | Sep 28 |
| 2010 | May 7 | no data | Apr 15 | no data |
| 2009 | May 21 | no data | May 16 | no data |
| 2008 | May 27 | no data | May 27 | no data |
| 2007 | May 29 | Sep 29 | May 29 | Oct 8 |
| 2006 | May 30 | Aug 21 | May 8 | Sep 30 |
| 2005 | May 16 | Sep 1 | May 16 | Oct 10 |
| 2004 | Apr 28 | Sep 4 | Apr 25 | Sep 14 |
| 2003 | May 26 | Sep 7 | Apr 19 | Sep 14 |
| 2002 | May 14 | Sep 10 | May 11 | Sep 21 |
| 2001 | May 26 | Sep 10 | May 6 | Oct 7 |
| 2000 | May 12 | Sep 16 | Apr 30 | Sep 19 |
| 1999 | May 27 | Sep 26 | May 3 | Sep 26 |
| 1998 | Apr 29 | Aug 29 | Apr 29 | Sep 28 |
| 1997 | May 8 | Sep 28 | May 1 | Oct 2 |
| 1996 | May 26 | Sep 8 | May 2 | Oct 2 |
| 1995 | May 27 | Sep 30 | May 2 | Oct 4 |
| 1994 | May 9 | Aug 29 | Apr 17 | Sep 25 |
| 1993 | May 10 | no data | Apr 25 | no data |
| 1992 | May 19 | Sep 10 | May 15 | Sep 10 |
| 1991 | Jun 8 | no data | Apr 18 | no data |
| 1990 | May 21 | Sep 15 | Apr 28 | Sep 25 |
| 1989 | May 17 | Sep 28 | May 6 | Oct 12 |
| 1988 | Jun 1 | Sep 3 | May 1 | Sep 22 |
| 1987 | May 14 | Aug 31 | May 10 | Sep 14 |
| 1986 | Jun 11 | Sep 25 | May 21 | Oct 6 |
| 1985 | Jun 17 | Sep 11 | May 22 | Sep 21 |
| 1984 | May 31 | Aug 30 | May 13 | Oct 10 |
| 1983 | May 27 | Aug 14 | May 5 | Sep 23 |
| 1982 | May 20 | Sep 22 | May 5 | Oct 3 |
| 1981 | May 22 | Sep 22 | May 2 | Sep 22 |
| 1980 | May 6 | Sep 5 | May 5 | Sep 5 |
| 1979 | Jun 5 | Aug 31 | May 19 | Sep 6 |
| 1978 | May 25 | Sep 19 | May 21 | Sep 23 |
| 1977 | Jul 8 | Sep 19 | May 29 | Sep 24 |
| 1976 | Jun 26 | Aug 30 | Jun 23 | Sep 5 |
| 1975 | Jul 2 | Aug 23 | Jun 28 | Sep 9 |
| 1974 | Jul 31 | Aug 19 | Jul 11 | Aug 22 |
| 1973 | Jul 11 | Aug 14 | Jun 5 | Aug 29 |
| 1972 | Jun 25 | Aug 29 | Jun 19 | Sep 20 |
| 1971 | Jul 6 | Aug 27 | May 26 | Sep 25 |
| 1970 | Jul 25 | Aug 27 | Jul 8 | Sep 3 |
| 1969 | May 30 | Aug 11 | May 23 | Sep 11 |
| 1968 | Jul 20 | Aug 29 | Jun 17 | Sep 14 |
| 1967 | May 29 | Sep 5 | May 29 | Sep 26 |
| 1966 | no data | Aug 5 | no data | Aug 5 |
| 1965 | Jun 28 | no data | May 17 | no data |
| 1964 | Jul 1 | Sep 6 | May 29 | Oct 4 |
| 1963 | Jun 29 | Aug 6 | May 25 | Aug 6 |
| 1962 | May 31 | Aug 31 | May 10 | Sep 12 |
| 1961 | Jun 3 | Aug 3 | May 30 | Oct 6 |
| 1960 | no data | Sep 4 | no data | Sep 5 |
"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.