Frost history / Jefferson Wwtp, WI
Jefferson Wwtp, WI: frost dates by year
Last spring and first fall frost at NOAA station USC00474108, 2005 to 2025, measured from daily minimum temperatures.
Elevation 783 ft, 42.994, -88.804. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Apr 26 | Oct 17 |
| Earliest | Apr 10 (2006) | Oct 4 (2008) |
| Latest | May 16 (2016) | Nov 12 (2016) |
| Trend | 2.9 days later per decade | little change (less than half a day per decade) |
| Years with data | 19 | 21 |
At 28°F (hard freeze) the median last spring date is Apr 10 and the median first fall date is Oct 30.
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 |
|---|---|---|---|---|
| 2025 | Apr 17 | Oct 24 | Apr 9 | Nov 2 |
| 2024 | Apr 26 | Oct 16 | Apr 7 | Nov 21 |
| 2023 | Apr 29 | Oct 18 | Apr 28 | Oct 30 |
| 2022 | no data | Oct 8 | no data | Nov 13 |
| 2021 | Apr 22 | Oct 24 | Apr 22 | Nov 3 |
| 2020 | no data | Oct 17 | no data | Oct 28 |
| 2019 | Apr 29 | Oct 14 | Apr 16 | Oct 30 |
| 2018 | Apr 30 | Oct 13 | Apr 30 | Oct 18 |
| 2017 | May 7 | Oct 29 | Apr 25 | Nov 6 |
| 2016 | May 16 | Nov 12 | Apr 10 | Nov 12 |
| 2015 | Apr 26 | Oct 17 | Apr 24 | Oct 17 |
| 2014 | Apr 27 | Oct 11 | Apr 16 | Nov 1 |
| 2013 | Apr 21 | Oct 22 | Apr 21 | Oct 22 |
| 2012 | Apr 27 | Oct 12 | Mar 11 | Oct 27 |
| 2011 | Apr 21 | Oct 21 | Apr 1 | Nov 4 |
| 2010 | Apr 18 | Oct 22 | Apr 9 | Nov 6 |
| 2009 | Apr 16 | Oct 10 | Apr 8 | Oct 11 |
| 2008 | Apr 30 | Oct 4 | Apr 2 | Oct 28 |
| 2007 | Apr 17 | Oct 28 | Apr 11 | Nov 7 |
| 2006 | Apr 10 | Oct 12 | Apr 9 | Oct 12 |
| 2005 | May 4 | Oct 27 | Mar 29 | Oct 28 |
"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.