Zion Np, UT: frost dates by year

Last spring and first fall frost at NOAA station USC00429717, 1951 to 2025, measured from daily minimum temperatures.

Elevation 4,038 ft, 37.209, -112.981. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 18	Oct 31
Earliest	Mar 5 (2004)	Oct 4 (1969)
Latest	May 22 (2021)	Dec 1 (2025)
Trend	little change (less than half a day per decade)	little change (less than half a day per decade)
Years with data	75	72

At 28°F (hard freeze) the median last spring date is Apr 2 and the median first fall date is Nov 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	Apr 21	Dec 1	Apr 5	Dec 3
2024	Mar 27	Oct 30	Mar 9	Oct 30
2023	Apr 8	Oct 29	Apr 8	Oct 29
2022	Apr 25	Oct 24	Apr 13	Nov 4
2021	May 22	Oct 13	Mar 31	Nov 18
2020	Apr 14	Oct 26	Apr 14	Oct 26
2019	Mar 16	Oct 10	Mar 15	Oct 28
2018	Apr 22	Oct 15	Mar 27	Nov 8
2017	May 18	Nov 18	Mar 7	Dec 4
2016	Mar 25	Nov 18	Feb 5	Nov 18
2015	Apr 17	Nov 5	Mar 5	Nov 17
2014	Apr 14	Nov 4	Apr 6	Nov 16
2013	Apr 17	Nov 2	Mar 24	Nov 5
2012	Apr 3	Nov 11	Mar 21	Nov 12
2011	May 1	Oct 27	Apr 30	Oct 27
2010	Apr 7	no data	Apr 7	no data
2009	Apr 17	no data	Apr 17	no data
2008	Apr 21	Oct 12	Mar 18	Oct 12
2007	Mar 30	Nov 21	Mar 4	Nov 21
2006	Apr 18	Oct 18	Apr 18	Nov 10
2005	Apr 5	Nov 15	Mar 26	Nov 22
2004	Mar 5	Nov 2	Mar 5	Nov 2
2003	Apr 6	Nov 18	Apr 6	Nov 23
2002	Mar 25	Nov 1	Mar 25	Nov 2
2001	May 4	Oct 13	Apr 12	Nov 26
2000	Mar 23	Nov 5	Feb 25	Nov 7
1999	Apr 16	Oct 17	Apr 10	Nov 23
1998	Apr 18	Oct 17	Apr 17	Nov 6
1997	May 2	Oct 25	Apr 11	Dec 2
1996	Apr 20	Oct 17	Apr 20	Oct 20
1995	Apr 23	Nov 2	Mar 30	Nov 27
1994	Apr 26	Oct 16	Apr 25	Nov 4
1993	May 5	Oct 27	Apr 13	Nov 2
1992	Mar 9	Nov 4	Feb 3	Nov 4
1991	Apr 28	Oct 28	Apr 13	Oct 31
1990	Mar 16	Oct 8	Mar 16	Nov 3
1989	Apr 27	Oct 28	Mar 5	Oct 29
1988	May 2	Nov 15	Apr 1	Nov 15
1987	Apr 20	Nov 15	Mar 30	Nov 16
1986	May 9	Nov 4	Mar 19	Nov 7
1985	Apr 26	Nov 1	Mar 31	Nov 13
1984	Apr 27	Oct 16	Apr 27	Oct 16
1983	Apr 14	Nov 8	Apr 4	Nov 8
1982	Apr 20	Oct 9	Mar 6	Nov 26
1981	Apr 4	Oct 30	Apr 4	Oct 30
1980	Apr 24	Oct 23	Apr 2	Oct 28
1979	May 10	Nov 1	Apr 11	Nov 20
1978	Apr 17	Nov 13	Feb 19	Nov 16
1977	Apr 15	Nov 8	Apr 4	Nov 9
1976	Apr 19	Oct 27	Mar 30	Oct 27
1975	May 6	no data	May 6	no data
1974	Apr 13	Nov 23	Apr 13	Nov 23
1973	Apr 21	Oct 30	Apr 21	Nov 20
1972	Apr 15	Oct 30	Mar 30	Oct 30
1971	Mar 19	Oct 29	Mar 15	Oct 29
1970	May 1	Oct 8	Apr 29	Oct 27
1969	Apr 26	Oct 4	Apr 25	Oct 4
1968	Apr 23	Nov 6	Apr 23	Nov 8
1967	May 14	Nov 24	May 1	Nov 25
1966	Apr 22	Oct 14	Apr 20	Nov 9
1965	May 8	Oct 16	May 8	Nov 26
1964	May 8	Nov 3	Apr 25	Nov 14
1963	Apr 22	Nov 8	Apr 18	Nov 22
1962	Apr 11	Nov 17	Mar 24	Nov 17
1961	Apr 11	Oct 10	Mar 7	Oct 29
1960	Mar 17	Nov 14	Mar 15	Nov 28
1959	Mar 25	Nov 5	Mar 16	Nov 27
1958	Apr 5	Nov 15	Apr 5	Nov 16
1957	Apr 23	Nov 6	Feb 5	Nov 17
1956	Apr 15	Oct 25	Mar 15	Nov 2
1955	Apr 27	Nov 15	Apr 4	Nov 16
1954	Mar 31	Oct 25	Mar 18	Nov 30
1953	May 10	Oct 24	Apr 10	Nov 19
1952	Mar 24	Nov 9	Mar 24	Nov 9
1951	Mar 19	Nov 2	Mar 18	Nov 2

"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.