Frost history / Seattle Boeing Fld, WA
Seattle Boeing Fld, WA: frost dates by year
Last spring and first fall frost at NOAA station USW00024234, 1951 to 2024, measured from daily minimum temperatures.
Elevation 20 ft, 47.530, -122.301. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Mar 20 | Nov 11 |
| Earliest | Jan 15 (2016) | Oct 27 (2023) |
| Latest | May 17 (1999) | Dec 12 (1962) |
| Trend | 2.1 days earlier per decade | little change (less than half a day per decade) |
| Years with data | 41 | 39 |
At 28°F (hard freeze) the median last spring date is Feb 23 and the median first fall date is Nov 28.
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 |
|---|---|---|---|---|
| 2024 | Mar 8 | Dec 1 | Mar 7 | none |
| 2023 | Mar 27 | Oct 27 | Mar 5 | Oct 28 |
| 2022 | Mar 10 | Nov 9 | Mar 10 | Nov 18 |
| 2021 | Apr 11 | Nov 17 | Feb 13 | Dec 26 |
| 2020 | Apr 13 | Nov 8 | none | Dec 24 |
| 2019 | Mar 11 | Oct 30 | Mar 10 | Nov 29 |
| 2018 | Mar 15 | Nov 9 | Feb 23 | Dec 6 |
| 2017 | Mar 19 | Dec 7 | Feb 2 | Dec 11 |
| 2016 | Jan 15 | no data | Jan 3 | no data |
| 2015 | Mar 4 | Nov 26 | Jan 1 | Nov 28 |
| 2014 | Feb 8 | Nov 12 | Feb 7 | Nov 14 |
| 2013 | Mar 9 | Nov 21 | Jan 16 | Dec 4 |
| 2012 | Mar 23 | Nov 9 | Mar 7 | none |
| 2011 | Mar 4 | Nov 2 | Feb 26 | Dec 5 |
| 2010 | Mar 9 | Nov 22 | none | Nov 22 |
| 2009 | Apr 4 | Nov 14 | Mar 11 | Dec 4 |
| 2008 | Apr 3 | Nov 23 | Jan 26 | Dec 14 |
| 2007 | Mar 21 | Nov 2 | Feb 2 | Nov 23 |
| 2006 | Mar 19 | Oct 30 | Feb 20 | Nov 28 |
| 2005 | Feb 24 | Nov 15 | Feb 23 | Nov 28 |
| 2004 | Mar 2 | Nov 20 | Jan 6 | Nov 29 |
| 2003 | Feb 26 | Oct 31 | Feb 25 | Nov 1 |
| 2002 | Mar 22 | Oct 30 | Mar 2 | Nov 1 |
| 2001 | Apr 29 | Dec 11 | Mar 3 | Dec 24 |
| 2000 | Mar 20 | Nov 10 | Feb 19 | Nov 11 |
| 1999 | May 17 | Dec 3 | Jan 24 | none |
| 1965 | Mar 24 | no data | Mar 19 | no data |
| 1964 | Mar 24 | Nov 28 | none | Dec 15 |
| 1963 | Apr 2 | Nov 20 | Jan 30 | Dec 11 |
| 1962 | Mar 28 | Dec 12 | Mar 12 | Dec 24 |
| 1961 | Apr 20 | Nov 5 | Jan 27 | Nov 16 |
| 1960 | Mar 4 | Oct 29 | Mar 3 | Dec 7 |
| 1959 | Mar 20 | Nov 5 | Jan 5 | Nov 13 |
| 1958 | Mar 16 | Nov 15 | none | Nov 16 |
| 1957 | Feb 22 | Nov 4 | Feb 21 | none |
| 1956 | Mar 16 | Nov 18 | Mar 12 | Nov 19 |
| 1955 | Mar 20 | Nov 11 | Mar 20 | Nov 11 |
| 1954 | May 1 | Dec 2 | Mar 29 | Dec 19 |
| 1953 | Mar 14 | Nov 3 | Mar 1 | none |
| 1952 | Apr 8 | Nov 2 | Jan 17 | Nov 23 |
| 1951 | Apr 21 | Nov 1 | Mar 6 | Nov 24 |
"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.