Frost history / Portland Troutdale Ap, OR
Portland Troutdale Ap, OR: frost dates by year
Last spring and first fall frost at NOAA station USW00024242, 1998 to 2024, measured from daily minimum temperatures.
Elevation 29 ft, 45.551, -122.409. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Mar 23 | Nov 10 |
| Earliest | Feb 24 (2017) | Oct 10 (2006) |
| Latest | Apr 24 (2000) | Dec 29 (1999) |
| Trend | 5.9 days earlier per decade | 6.2 days later per decade |
| Years with data | 25 | 27, 1 with no freeze |
At 28°F (hard freeze) the median last spring date is Feb 17 and the median first fall date is Dec 4.
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 | no data | Nov 30 | no data | none |
| 2023 | Mar 27 | Dec 23 | Feb 25 | none |
| 2022 | Mar 12 | Nov 9 | Feb 24 | Dec 17 |
| 2021 | Apr 14 | Nov 22 | Feb 14 | Dec 29 |
| 2020 | Mar 22 | Oct 27 | Feb 4 | none |
| 2019 | Mar 9 | Oct 28 | Mar 5 | none |
| 2018 | Apr 3 | Dec 3 | Feb 23 | none |
| 2017 | Feb 24 | Nov 19 | Jan 24 | none |
| 2016 | Mar 17 | Dec 6 | Jan 3 | Dec 7 |
| 2015 | Mar 8 | Nov 25 | Jan 1 | Nov 26 |
| 2014 | Mar 23 | Nov 12 | Feb 8 | Dec 2 |
| 2013 | Mar 9 | Oct 29 | Jan 20 | Nov 20 |
| 2012 | Mar 23 | none | Mar 7 | none |
| 2011 | Apr 18 | Nov 6 | Feb 26 | Dec 3 |
| 2010 | Mar 18 | Nov 20 | none | Nov 23 |
| 2009 | Apr 4 | Nov 14 | Feb 27 | Dec 4 |
| 2008 | Apr 11 | Dec 5 | Apr 2 | Dec 6 |
| 2007 | Apr 20 | Oct 26 | Feb 3 | Dec 9 |
| 2006 | Mar 19 | Oct 10 | Mar 13 | Dec 17 |
| 2005 | Mar 18 | Nov 7 | Feb 15 | Nov 27 |
| 2004 | Apr 2 | Nov 5 | Jan 21 | Nov 21 |
| 2003 | Mar 2 | Oct 31 | Feb 9 | Nov 1 |
| 2002 | Mar 7 | Oct 25 | Mar 7 | none |
| 2001 | Apr 14 | Nov 7 | Feb 26 | none |
| 2000 | Apr 24 | Nov 11 | Feb 18 | Nov 11 |
| 1999 | Apr 2 | Dec 29 | Jan 5 | Dec 29 |
| 1998 | no data | Oct 30 | no data | Dec 18 |
"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.