Shaw 4ENE, CO: frost dates by year

Last spring and first fall frost at NOAA station USC00057560, 1997 to 2020, measured from daily minimum temperatures.

Elevation 5,000 ft, 39.572, -103.292. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 14	Oct 5
Earliest	Apr 17 (2012)	Sep 12 (2014)
Latest	Jun 8 (2007)	Oct 24 (2015)
Trend	5.4 days earlier per decade	0.8 days later per decade
Years with data	23	19

At 28°F (hard freeze) the median last spring date is May 5 and the median first fall date is Oct 10.

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
2020	May 12	no data	Apr 20	no data
2019	May 25	Oct 3	May 22	Oct 10
2018	Apr 27	Oct 10	Apr 25	Oct 10
2017	May 4	Oct 9	Apr 28	Oct 10
2016	May 3	Oct 5	May 2	Oct 5
2015	May 20	Oct 24	May 11	Oct 28
2014	May 15	Sep 12	May 14	Oct 28
2013	May 6	Oct 5	May 5	Oct 5
2012	Apr 17	Oct 4	Apr 16	Oct 7
2011	May 16	Oct 10	May 14	Oct 18
2010	May 25	no data	May 13	no data
2009	May 14	Sep 28	Apr 10	Oct 2
2008	no data	Oct 7	no data	Oct 24
2007	Jun 8	no data	Apr 14	no data
2006	May 15	no data	May 11	no data
2005	May 13	Oct 6	May 13	Oct 23
2004	May 14	Oct 14	Apr 13	Oct 14
2003	May 11	no data	Apr 9	no data
2002	May 25	Oct 13	May 9	Oct 15
2001	May 21	Oct 5	Apr 23	Oct 6
2000	May 13	Sep 23	May 13	Sep 25
1999	May 12	Sep 29	May 7	Sep 29
1998	Jun 5	Oct 5	Apr 30	Oct 18
1997	May 12	Oct 9	May 12	Oct 13

"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.