Frost history / Ishpeming Wwtp, MI
Ishpeming Wwtp, MI: frost dates by year
Last spring and first fall frost at NOAA station USC00204130, 2007 to 2025, measured from daily minimum temperatures.
Elevation 1,406 ft, 46.491, -87.689. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 29 | Oct 1 |
| Earliest | May 10 (2012) | Sep 9 (2017) |
| Latest | Jun 4 (2013) | Oct 18 (2021) |
| Trend | 3.2 days later per decade | 4.5 days later per decade |
| Years with data | 18 | 19 |
At 28°F (hard freeze) the median last spring date is May 12 and the median first fall date is Oct 13.
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 | Jun 1 | Oct 8 | May 9 | Oct 21 |
| 2024 | May 30 | Oct 4 | Apr 26 | Oct 8 |
| 2023 | May 25 | Oct 7 | May 24 | Oct 11 |
| 2022 | May 23 | Sep 23 | May 5 | Oct 9 |
| 2021 | May 30 | Oct 18 | May 29 | Oct 18 |
| 2020 | May 31 | Sep 18 | May 14 | Sep 19 |
| 2019 | Jun 3 | Oct 5 | May 9 | Oct 18 |
| 2018 | May 13 | Oct 5 | May 13 | Oct 13 |
| 2017 | May 20 | Sep 9 | May 19 | Oct 26 |
| 2016 | Jun 3 | Oct 9 | May 18 | Oct 14 |
| 2015 | Jun 1 | Sep 30 | May 22 | Sep 30 |
| 2014 | May 19 | Sep 13 | May 6 | Oct 11 |
| 2013 | Jun 4 | Sep 16 | May 25 | Oct 15 |
| 2012 | May 10 | Sep 19 | Apr 30 | Oct 8 |
| 2011 | May 28 | Sep 16 | May 5 | Sep 16 |
| 2010 | May 11 | Sep 19 | May 11 | Oct 22 |
| 2009 | Jun 3 | Oct 1 | May 12 | Oct 1 |
| 2008 | May 27 | Oct 4 | May 4 | Oct 18 |
| 2007 | no data | Oct 13 | no data | Oct 14 |
"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.