Frost history / Ontario Muni Ap, OR
Ontario Muni Ap, OR: frost dates by year
Last spring and first fall frost at NOAA station USW00024162, 1997 to 2024, measured from daily minimum temperatures.
Elevation 2,190 ft, 44.021, -117.013. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Apr 30 | Oct 11 |
| Earliest | Apr 6 (2016) | Sep 18 (2003) |
| Latest | May 23 (2010) | Nov 5 (2015) |
| Trend | 3.0 days earlier per decade | 7.4 days later per decade |
| Years with data | 27 | 27 |
At 28°F (hard freeze) the median last spring date is Apr 11 and the median first fall date is Oct 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 |
|---|---|---|---|---|
| 2024 | Apr 30 | Oct 24 | Apr 30 | Oct 25 |
| 2023 | Apr 20 | Oct 27 | Apr 19 | Oct 29 |
| 2022 | May 10 | Oct 24 | Apr 10 | Oct 27 |
| 2021 | Apr 27 | Oct 15 | Apr 9 | Nov 8 |
| 2020 | Apr 18 | Oct 16 | Apr 17 | Oct 23 |
| 2019 | May 1 | Oct 7 | Mar 20 | Oct 11 |
| 2018 | Apr 18 | no data | Apr 18 | no data |
| 2017 | May 13 | Oct 6 | Apr 4 | Oct 15 |
| 2016 | Apr 6 | Oct 2 | Mar 26 | Oct 12 |
| 2015 | Apr 27 | Nov 5 | Apr 3 | Nov 7 |
| 2014 | Apr 29 | Oct 22 | Apr 14 | Nov 12 |
| 2013 | May 2 | Oct 5 | May 1 | Nov 4 |
| 2012 | Apr 8 | Oct 4 | Apr 7 | Oct 6 |
| 2011 | May 5 | Oct 18 | Apr 27 | Oct 27 |
| 2010 | May 23 | Oct 13 | Apr 10 | Nov 13 |
| 2009 | May 13 | Oct 1 | Apr 6 | Oct 11 |
| 2008 | May 10 | Oct 13 | Apr 26 | Oct 22 |
| 2007 | May 4 | Oct 11 | Apr 11 | Oct 27 |
| 2006 | Apr 20 | Oct 11 | Apr 19 | Oct 22 |
| 2005 | Apr 16 | Sep 26 | Apr 15 | Nov 9 |
| 2004 | Apr 16 | Oct 19 | Mar 29 | Oct 25 |
| 2003 | May 19 | Sep 18 | Apr 7 | Oct 31 |
| 2002 | May 8 | Oct 12 | May 8 | Oct 12 |
| 2001 | Apr 29 | Oct 6 | Apr 16 | Oct 10 |
| 2000 | May 12 | Sep 24 | Mar 24 | Sep 24 |
| 1999 | May 11 | Sep 28 | May 11 | Sep 28 |
| 1998 | Apr 18 | Oct 6 | Mar 20 | Oct 17 |
| 1997 | no data | Oct 8 | no data | Oct 8 |
"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.