Guffey 9SE, CO: frost dates by year

Last spring and first fall frost at NOAA station USC00053652, 2010 to 2025, measured from daily minimum temperatures.

Elevation 8,915 ft, 38.687, -105.392. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 24	Sep 27
Earliest	May 4 (2018)	Sep 8 (2020)
Latest	Jun 15 (2014)	Oct 19 (2024)
Trend	3.6 days earlier per decade	7.3 days later per decade
Years with data	16	16

At 28°F (hard freeze) the median last spring date is May 15 and the median first fall date is Oct 9.

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 20	Oct 7	May 15	Oct 13
2024	May 23	Oct 19	May 23	Oct 30
2023	May 11	Oct 7	Apr 28	Oct 13
2022	Jun 1	Oct 8	May 25	Oct 24
2021	May 13	Sep 21	May 12	Oct 13
2020	Jun 9	Sep 8	May 11	Sep 8
2019	May 30	Sep 22	May 30	Oct 7
2018	May 4	Sep 26	Apr 27	Oct 9
2017	May 28	Oct 3	May 23	Oct 9
2016	May 28	Sep 10	May 17	Oct 4
2015	May 21	Sep 19	May 11	Oct 28
2014	Jun 15	Sep 12	May 15	Sep 12
2013	May 21	Sep 28	May 10	Sep 28
2012	May 24	Oct 4	May 8	Oct 4
2011	May 21	Sep 21	May 20	Oct 7
2010	May 25	Oct 9	May 16	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.