Rifle 3ENE, CO: frost dates by year

Last spring and first fall frost at NOAA station USC00057033, 2010 to 2025, measured from daily minimum temperatures.

Elevation 5,469 ft, 39.557, -107.726. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 25	Sep 27
Earliest	Apr 27 (2018)	Sep 7 (2010)
Latest	Jun 9 (2014)	Oct 22 (2024)
Trend	10.6 days earlier per decade	6.5 days later per decade
Years with data	16	16

At 28°F (hard freeze) the median last spring date is May 10 and the median first fall date is Oct 14.

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 6	Apr 29	Oct 17
2024	May 24	Oct 22	May 24	Oct 25
2023	May 8	Sep 24	Apr 29	Oct 26
2022	May 25	Oct 13	May 21	Oct 16
2021	May 25	Sep 21	Apr 29	Oct 15
2020	May 25	Sep 9	May 8	Sep 28
2019	May 25	Sep 22	May 2	Oct 3
2018	Apr 27	Sep 27	Apr 27	Oct 15
2017	May 28	Sep 25	May 20	Oct 3
2016	May 28	Sep 10	May 12	Oct 5
2015	May 20	Oct 13	May 11	Oct 24
2014	Jun 9	Oct 3	May 15	Oct 14
2013	Jun 1	Sep 28	May 4	Sep 28
2012	May 29	Oct 4	May 1	Oct 7
2011	Jun 4	Oct 7	May 31	Oct 7
2010	May 31	Sep 7	May 31	Oct 14

"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.