Ann Arbor Se, MI: frost dates by year

Last spring and first fall frost at NOAA station USC00200228, 2003 to 2025, measured from daily minimum temperatures.

Elevation 832 ft, 42.242, -83.693. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 6	Oct 15
Earliest	Apr 16 (2019)	Sep 19 (2020)
Latest	May 28 (2008)	Oct 26 (2017)
Trend	8.0 days earlier per decade	4.6 days later per decade
Years with data	22	23

At 28°F (hard freeze) the median last spring date is Apr 26 and the median first fall date is Oct 22.

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 18	Oct 25	Apr 18	Nov 2
2024	Apr 26	Oct 17	Apr 26	Oct 27
2023	May 18	Oct 23	Apr 27	Oct 31
2022	Apr 29	Oct 8	Apr 29	Oct 9
2021	May 6	Oct 24	May 2	Nov 3
2020	May 14	Sep 19	May 13	Oct 16
2019	Apr 16	Oct 15	Apr 2	Nov 6
2018	Apr 30	Oct 15	Apr 29	Oct 16
2017	May 10	Oct 26	Apr 9	Oct 26
2016	Apr 24	Oct 14	Apr 15	Nov 12
2015	Apr 29	Oct 17	Apr 25	Oct 17
2014	Apr 27	Oct 11	Apr 17	Oct 20
2013	May 13	Oct 22	May 13	Oct 22
2012	Apr 30	Oct 8	Apr 30	Oct 8
2011	May 4	Oct 22	Apr 6	Oct 22
2010	May 10	Oct 19	Apr 11	Nov 1
2009	May 18	Oct 1	Apr 16	Oct 11
2008	May 28	Oct 4	May 1	Oct 19
2007	May 13	Oct 13	Apr 15	Oct 29
2006	May 23	Oct 13	Apr 26	Oct 15
2005	May 6	Oct 17	May 5	Oct 27
2004	May 5	Oct 3	May 4	Oct 5
2003	no data	Oct 2	no data	Oct 5

"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.