Frost history / Jefferson, NH
Jefferson, NH: frost dates by year
Last spring and first fall frost at NOAA station USC00274329, 2011 to 2025, measured from daily minimum temperatures.
Elevation 1,235 ft, 44.417, -71.501. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 9 | Sep 28 |
| Earliest | Apr 23 (2011) | Sep 15 (2014) |
| Latest | Jun 1 (2020) | Oct 24 (2023) |
| Trend | 0.9 days later per decade | 13.4 days later per decade |
| Years with data | 15 | 15 |
At 28°F (hard freeze) the median last spring date is Apr 25 and the median first fall date is Oct 17.
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 | May 2 | Sep 21 | Apr 22 | Oct 10 |
| 2024 | Apr 28 | Oct 13 | Apr 27 | Oct 17 |
| 2023 | May 27 | Oct 24 | May 18 | Oct 31 |
| 2022 | May 7 | Sep 30 | Apr 22 | Oct 11 |
| 2021 | May 7 | Oct 24 | Apr 23 | Nov 3 |
| 2020 | Jun 1 | Sep 15 | May 13 | Sep 19 |
| 2019 | May 10 | Sep 19 | Apr 29 | Oct 5 |
| 2018 | May 12 | Oct 15 | Apr 23 | Oct 18 |
| 2017 | May 9 | Oct 13 | Apr 14 | Nov 8 |
| 2016 | May 16 | Sep 26 | Apr 30 | Oct 15 |
| 2015 | May 23 | Oct 5 | Apr 29 | Oct 18 |
| 2014 | May 8 | Sep 15 | Apr 25 | Nov 3 |
| 2013 | May 27 | Sep 17 | Apr 23 | Oct 26 |
| 2012 | May 1 | Sep 28 | Apr 29 | Oct 13 |
| 2011 | Apr 23 | Sep 17 | Apr 23 | Oct 7 |
"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.