Carlisle Wtp, PA: frost dates by year

Last spring and first fall frost at NOAA station USC00361920, 2008 to 2025, measured from daily minimum temperatures.

Elevation 430 ft, 40.226, -77.189. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 18	Oct 20
Earliest	Mar 27 (2024)	Oct 11 (2025)
Latest	May 14 (2013)	Nov 8 (2014)
Trend	little change (less than half a day per decade)	1.8 days earlier per decade
Years with data	18	18

At 28°F (hard freeze) the median last spring date is Apr 4 and the median first fall date is Nov 2.

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 18	Oct 11	Apr 9	Oct 28
2024	Mar 27	Oct 20	Mar 25	Nov 13
2023	Apr 27	Oct 24	Apr 10	Nov 2
2022	May 1	Oct 19	Apr 19	Oct 30
2021	Apr 24	Nov 3	Apr 4	Nov 4
2020	May 10	Oct 17	Apr 18	Nov 17
2019	Apr 4	Oct 20	Apr 4	Nov 2
2018	May 2	Oct 19	Apr 12	Nov 11
2017	Apr 10	Oct 27	Mar 24	Nov 11
2016	Apr 15	Oct 15	Apr 11	Oct 27
2015	Apr 13	Oct 18	Apr 3	Oct 19
2014	Apr 19	Nov 8	Apr 18	Nov 8
2013	May 14	Oct 23	Apr 5	Oct 26
2012	Apr 30	Oct 13	Mar 12	Oct 13
2011	Apr 7	Oct 30	Mar 31	Oct 30
2010	Apr 15	Oct 23	Mar 29	Nov 2
2009	Apr 17	Oct 19	Apr 13	Nov 7
2008	Apr 17	Oct 20	Apr 4	Oct 20

"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.