Algonac Wwtp, MI: frost dates by year

Last spring and first fall frost at NOAA station USC00200106, 2005 to 2025, measured from daily minimum temperatures.

Elevation 580 ft, 42.616, -82.544. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 4	Oct 25
Earliest	Apr 15 (2007)	Oct 8 (2022)
Latest	May 24 (2025)	Nov 3 (2021)
Trend	9.7 days later per decade	0.6 days earlier per decade
Years with data	14	16

At 28°F (hard freeze) the median last spring date is Apr 16 and the median first fall date is Nov 6.

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 24	Oct 26	Apr 17	Nov 10
2024	Apr 26	Oct 27	Apr 25	Nov 28
2023	May 19	Oct 23	Apr 10	Oct 31
2022	May 8	Oct 8	May 8	Nov 14
2021	May 11	Nov 3	Apr 24	Nov 5
2020	May 12	Oct 16	May 12	Oct 31
2019	Apr 29	Oct 26	Apr 2	Nov 6
2018	Apr 28	Oct 18	Apr 21	Oct 18
2017	May 10	Oct 25	Mar 23	Nov 7
2011	no data	Oct 28	no data	Nov 18
2010	May 10	Nov 1	Apr 10	Nov 1
2009	Apr 23	Oct 11	Apr 12	Nov 6
2008	Apr 30	Oct 22	Apr 30	Oct 22
2007	Apr 15	Nov 2	Apr 14	Nov 19
2006	Apr 28	Oct 13	Apr 9	Nov 3
2005	no data	Oct 29	no data	Nov 11

"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.