Frost history / Hennepin, IL
Hennepin, IL: frost dates by year
Last spring and first fall frost at NOAA station USC00114012, 2012 to 2025, measured from daily minimum temperatures.
Elevation 515 ft, 41.254, -89.338. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Apr 21 | Oct 25 |
| Earliest | Apr 1 (2017) | Oct 8 (2022) |
| Latest | May 9 (2020) | Nov 12 (2016) |
| Trend | 7.2 days later per decade | 5.5 days earlier per decade |
| Years with data | 14 | 14 |
At 28°F (hard freeze) the median last spring date is Apr 16 and the median first fall date is Oct 29.
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 16 | Oct 24 | Apr 8 | Nov 10 |
| 2024 | Apr 25 | Oct 16 | Apr 21 | Oct 17 |
| 2023 | Apr 27 | Oct 30 | Apr 25 | Oct 30 |
| 2022 | Apr 19 | Oct 8 | Apr 17 | Oct 19 |
| 2021 | Apr 22 | Nov 1 | Apr 22 | Nov 3 |
| 2020 | May 9 | Oct 17 | May 9 | Oct 28 |
| 2019 | Apr 28 | Oct 26 | Apr 15 | Oct 31 |
| 2018 | Apr 29 | Oct 16 | Apr 29 | Oct 21 |
| 2017 | Apr 1 | Oct 29 | Mar 22 | Oct 29 |
| 2016 | Apr 13 | Nov 12 | Apr 12 | Nov 12 |
| 2015 | Apr 24 | Oct 17 | Apr 4 | Oct 18 |
| 2014 | Apr 16 | Oct 30 | Apr 16 | Nov 1 |
| 2013 | Apr 20 | Oct 22 | Apr 4 | Oct 22 |
| 2012 | Apr 12 | Oct 27 | Apr 12 | Nov 4 |
"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.