Williamsport, PA: frost dates by year

Last spring and first fall frost at NOAA station USW00014778, 1951 to 2024, measured from daily minimum temperatures.

Elevation 520 ft, 41.243, -76.922. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 28	Oct 18
Earliest	Apr 9 (1955)	Sep 24 (1963)
Latest	May 25 (1956)	Nov 17 (1970)
Trend	little change (less than half a day per decade)	2.0 days later per decade
Years with data	74	74

At 28°F (hard freeze) the median last spring date is Apr 10 and the median first fall date is Nov 3.

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
2024	Apr 26	Oct 27	Mar 25	Nov 13
2023	May 18	Oct 31	Mar 30	Nov 12
2022	Apr 30	Oct 18	Apr 18	Nov 15
2021	Apr 23	Nov 3	Apr 3	Nov 5
2020	May 13	Nov 4	Apr 19	Nov 18
2019	Apr 29	Nov 2	Apr 3	Nov 8
2018	Apr 23	Oct 19	Apr 11	Nov 12
2017	Apr 9	Nov 1	Mar 23	Nov 10
2016	Apr 13	Oct 26	Apr 10	Nov 14
2015	Apr 26	Oct 18	Apr 2	Nov 23
2014	Apr 28	Nov 7	Apr 17	Nov 14
2013	May 14	Oct 25	Apr 5	Oct 26
2012	Apr 30	Oct 12	Mar 27	Oct 13
2011	Apr 22	Oct 28	Apr 6	Nov 5
2010	May 11	Oct 23	Mar 27	Nov 2
2009	Apr 24	Oct 19	Apr 13	Nov 7
2008	Apr 16	Oct 19	Apr 3	Oct 20
2007	Apr 14	Oct 29	Apr 11	Nov 2
2006	Apr 28	Oct 13	Apr 9	Oct 15
2005	May 5	Oct 28	Mar 26	Nov 12
2004	Apr 28	Nov 4	Apr 6	Nov 9
2003	Apr 24	Oct 3	Apr 1	Nov 8
2002	May 22	Oct 22	Apr 7	Nov 4
2001	Apr 29	Oct 8	Apr 19	Oct 9
2000	Apr 13	Oct 9	Apr 13	Nov 7
1999	Apr 26	Oct 7	Apr 25	Nov 5
1998	Apr 28	Nov 1	Apr 7	Nov 3
1997	May 8	Oct 17	Apr 15	Oct 26
1996	May 14	Oct 4	May 14	Nov 2
1995	Apr 17	Oct 17	Apr 6	Nov 6
1994	May 14	Oct 12	Apr 23	Nov 11
1993	Apr 28	Oct 1	Mar 27	Oct 11
1992	Apr 29	Oct 6	Apr 13	Oct 19
1991	Apr 23	Sep 30	Apr 4	Oct 30
1990	May 12	Oct 20	Apr 19	Oct 30
1989	Apr 24	Oct 10	Apr 24	Nov 4
1988	Apr 26	Oct 12	Apr 19	Oct 14
1987	May 1	Oct 9	Apr 1	Oct 26
1986	May 4	Oct 10	Apr 13	Oct 31
1985	May 9	Oct 28	Apr 12	Oct 29
1984	Apr 22	Nov 2	Apr 10	Nov 3
1983	May 18	Oct 21	Mar 31	Oct 22
1982	Apr 29	Oct 17	Apr 22	Oct 23
1981	Apr 22	Oct 20	Apr 21	Oct 25
1980	Apr 17	Oct 22	Apr 17	Oct 24
1979	Apr 20	Oct 16	Apr 11	Nov 16
1978	May 1	Oct 18	Apr 3	Nov 20
1977	Apr 10	Oct 18	Apr 10	Oct 31
1976	May 13	Oct 18	Apr 12	Oct 19
1975	Apr 28	Oct 3	Apr 22	Oct 31
1974	May 8	Oct 3	Apr 11	Oct 19
1973	May 19	Oct 31	Apr 15	Nov 7
1972	Apr 28	Oct 10	Apr 10	Oct 10
1971	Apr 15	Nov 4	Mar 31	Nov 8
1970	Apr 13	Nov 17	Apr 13	Nov 23
1969	May 1	Oct 22	Apr 12	Oct 23
1968	May 7	Oct 6	Apr 7	Oct 30
1967	May 17	Oct 20	Apr 4	Oct 29
1966	May 11	Oct 7	May 5	Oct 27
1965	Apr 24	Sep 28	Apr 5	Oct 6
1964	Apr 11	Oct 7	Apr 10	Oct 12
1963	May 24	Sep 24	Apr 6	Nov 3
1962	May 10	Oct 25	Apr 17	Oct 25
1961	Apr 21	Oct 24	Apr 9	Nov 10
1960	May 2	Oct 22	Apr 11	Nov 7
1959	Apr 22	Oct 19	Apr 14	Oct 29
1958	May 10	Oct 6	Apr 10	Nov 8
1957	Apr 16	Oct 12	Apr 16	Nov 11
1956	May 25	Oct 11	Apr 25	Nov 10
1955	Apr 9	Oct 23	Mar 31	Nov 6
1954	Apr 13	Oct 8	Apr 4	Oct 8
1953	Apr 29	Oct 8	Apr 22	Nov 5
1952	Apr 12	Oct 4	Apr 12	Oct 21
1951	Apr 24	Sep 30	Mar 27	Nov 3

"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.