Catalina Sp, AZ: frost dates by year

Last spring and first fall frost at NOAA station USC00021357, 2009 to 2025, measured from daily minimum temperatures.

Elevation 2,707 ft, 32.418, -110.930. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 6	Nov 4
Earliest	Feb 22 (2014)	Oct 13 (2021)
Latest	May 1 (2011)	Dec 8 (2017)
Trend	9.2 days earlier per decade	6.2 days earlier per decade
Years with data	17	17

At 28°F (hard freeze) the median last spring date is Mar 15 and the median first fall date is Nov 23.

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	Apr 6	Nov 1	Feb 28	Nov 1
2024	Apr 8	Oct 31	Apr 7	Nov 7
2023	Apr 6	Nov 10	Apr 6	Dec 3
2022	Apr 16	Oct 25	Apr 14	Nov 4
2021	Mar 27	Oct 13	Mar 20	Dec 17
2020	Apr 11	Oct 27	Mar 29	Nov 26
2019	Mar 16	Oct 31	Mar 15	Oct 31
2018	Mar 20	Nov 12	Mar 2	Nov 12
2017	Mar 8	Dec 8	Feb 26	Dec 8
2016	Apr 2	Nov 18	Feb 28	Nov 30
2015	Apr 17	Nov 17	Feb 7	Nov 23
2014	Feb 22	Nov 4	Feb 5	Nov 17
2013	Apr 19	Oct 31	Mar 1	Dec 6
2012	Apr 6	Nov 11	Mar 20	Dec 10
2011	May 1	Nov 8	Mar 9	Dec 5
2010	May 1	Nov 10	Mar 21	Nov 10
2009	Apr 17	Oct 29	Apr 5	Oct 29

"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.