Montrose 8N, SD: frost dates by year

Last spring and first fall frost at NOAA station USC00395738, 1997 to 2013, measured from daily minimum temperatures.

Elevation 1,718 ft, 43.820, -97.202. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 5	Oct 6
Earliest	Apr 14 (2007)	Sep 14 (2007)
Latest	May 16 (2009)	Oct 28 (2010)
Trend	9.4 days later per decade	2.8 days later per decade
Years with data	13	17

At 28°F (hard freeze) the median last spring date is Apr 13 and the median first fall date is Oct 18.

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
2013	May 12	Oct 16	May 9	Oct 18
2012	Apr 17	Sep 19	Apr 15	Sep 19
2011	May 3	Oct 15	May 2	Oct 30
2010	May 10	Oct 28	Apr 9	Oct 28
2009	May 16	Oct 7	Apr 12	Oct 9
2008	May 11	Oct 16	May 3	Oct 26
2007	Apr 14	Sep 14	Apr 13	Nov 5
2006	May 5	Sep 20	Apr 9	Oct 12
2005	no data	Oct 7	no data	Oct 22
2004	May 14	Oct 2	Apr 13	Oct 2
2003	no data	Oct 1	no data	Oct 26
2002	May 10	Oct 8	Apr 9	Oct 14
2001	no data	Oct 6	no data	Oct 6
2000	Apr 17	Oct 6	Apr 16	Oct 6
1999	Apr 21	Sep 30	Apr 21	Oct 2
1998	Apr 17	Oct 1	Apr 2	Nov 3
1997	no data	Oct 14	no data	Oct 25

"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.