Nunn 7 Nne, CO: frost dates by year

Last spring and first fall frost at NOAA station USW00094074, 2003 to 2024, measured from daily minimum temperatures.

Elevation 5,390 ft, 40.807, -104.755. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 13	Sep 30
Earliest	Apr 26 (2007)	Sep 7 (2010)
Latest	May 22 (2024)	Oct 16 (2004)
Trend	3.1 days later per decade	1.4 days later per decade
Years with data	21	22

At 28°F (hard freeze) the median last spring date is May 5 and the median first fall date is Oct 11.

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
2024	May 22	Oct 1	May 22	Oct 25
2023	May 1	Oct 6	Apr 24	Oct 6
2022	May 22	Oct 8	May 22	Oct 17
2021	May 11	Oct 11	Apr 23	Oct 14
2020	May 11	Sep 8	May 8	Sep 28
2019	May 22	Oct 2	May 2	Oct 3
2018	Apr 28	Sep 25	Apr 27	Oct 13
2017	May 20	Oct 3	May 4	Oct 9
2016	May 12	Sep 10	May 12	Oct 5
2015	May 20	Sep 19	May 11	Oct 16
2014	May 14	Sep 12	May 13	Sep 12
2013	May 5	Oct 4	May 3	Oct 15
2012	May 9	Oct 4	Apr 18	Oct 7
2011	May 5	Sep 22	May 5	Oct 18
2010	May 13	Sep 7	May 13	Oct 19
2009	Apr 27	Sep 28	Apr 13	Sep 28
2008	May 14	Oct 7	May 11	Oct 13
2007	Apr 26	Oct 3	Apr 15	Oct 8
2006	May 15	Sep 17	May 11	Oct 13
2005	May 14	Sep 29	May 12	Oct 7
2004	May 14	Oct 16	Apr 24	Oct 30
2003	no data	Sep 18	no data	Sep 18

"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.