Frost history / Norristown, PA
Norristown, PA: frost dates by year
Last spring and first fall frost at NOAA station USC00366370, 1952 to 2025, measured from daily minimum temperatures.
Elevation 62 ft, 40.110, -75.337. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Apr 10 | Oct 30 |
| Earliest | Mar 24 (2017) | Oct 8 (1964) |
| Latest | May 10 (1966) | Nov 17 (2020) |
| Trend | little change (less than half a day per decade) | little change (less than half a day per decade) |
| Years with data | 47 | 53 |
At 28°F (hard freeze) the median last spring date is Mar 29 and the median first fall date is Nov 11.
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 10 | Nov 7 | Apr 10 | Nov 11 |
| 2024 | no data | Nov 3 | no data | Nov 14 |
| 2023 | Apr 4 | Nov 2 | Mar 21 | Nov 2 |
| 2022 | Apr 18 | Oct 9 | Mar 31 | Nov 15 |
| 2021 | Apr 4 | no data | Apr 4 | no data |
| 2020 | Apr 19 | Nov 17 | Mar 9 | Nov 19 |
| 2019 | Apr 3 | Nov 4 | Mar 13 | Nov 9 |
| 2018 | Apr 11 | Nov 11 | Mar 27 | Nov 16 |
| 2017 | Mar 24 | Nov 11 | Mar 24 | Nov 11 |
| 2016 | Apr 11 | Oct 26 | Apr 11 | Nov 14 |
| 2015 | Apr 25 | Oct 19 | Apr 1 | Oct 19 |
| 2014 | Apr 18 | Nov 8 | Mar 28 | Nov 8 |
| 2013 | Apr 15 | Oct 26 | Mar 24 | Nov 4 |
| 2012 | Apr 28 | Oct 13 | Mar 11 | Nov 6 |
| 2011 | no data | Oct 30 | no data | Nov 7 |
| 2009 | Apr 17 | no data | Mar 26 | no data |
| 2008 | no data | Oct 30 | no data | Nov 19 |
| 2007 | no data | Nov 8 | no data | Nov 24 |
| 2005 | Mar 26 | no data | Mar 16 | no data |
| 2004 | Apr 7 | Nov 9 | Apr 6 | Nov 10 |
| 2003 | Apr 9 | Oct 24 | Apr 1 | Oct 24 |
| 2001 | no data | Oct 9 | no data | Nov 12 |
| 2000 | no data | Oct 8 | no data | Nov 15 |
| 1986 | no data | Nov 13 | no data | Nov 14 |
| 1985 | Apr 11 | Oct 29 | Apr 10 | Dec 3 |
| 1984 | Apr 1 | Nov 3 | Mar 15 | Nov 20 |
| 1983 | Apr 22 | Oct 30 | Mar 30 | Nov 1 |
| 1982 | Apr 15 | Oct 19 | Apr 10 | Nov 16 |
| 1981 | Apr 23 | Oct 14 | Apr 16 | Oct 20 |
| 1980 | Apr 17 | Oct 31 | Mar 16 | Nov 3 |
| 1979 | Apr 15 | Oct 10 | Apr 8 | Nov 30 |
| 1978 | Apr 9 | Oct 18 | Mar 19 | Nov 26 |
| 1977 | Apr 10 | Nov 12 | Apr 10 | Nov 14 |
| 1976 | Apr 13 | Oct 19 | Apr 12 | Oct 27 |
| 1975 | no data | Oct 31 | no data | Dec 3 |
| 1972 | Apr 26 | Oct 19 | Apr 9 | Oct 20 |
| 1971 | Apr 9 | Nov 7 | Mar 28 | Nov 9 |
| 1970 | Apr 11 | Nov 17 | Mar 30 | Nov 23 |
| 1969 | Apr 1 | Oct 23 | Apr 1 | Oct 24 |
| 1968 | Apr 6 | Oct 31 | Mar 15 | Nov 21 |
| 1967 | Apr 4 | Oct 29 | Mar 20 | Nov 6 |
| 1966 | May 10 | Oct 31 | Mar 29 | Nov 21 |
| 1965 | Apr 5 | Oct 29 | Apr 3 | Oct 29 |
| 1964 | Apr 10 | Oct 8 | Apr 5 | Nov 21 |
| 1963 | Apr 6 | Nov 14 | Mar 24 | Dec 1 |
| 1962 | Apr 17 | Oct 25 | Apr 4 | Nov 7 |
| 1961 | Apr 9 | Oct 28 | Mar 18 | Nov 11 |
| 1960 | Apr 11 | Nov 7 | Mar 27 | Nov 8 |
| 1959 | Mar 29 | Oct 29 | Mar 29 | Nov 17 |
| 1958 | Apr 9 | Nov 8 | Mar 18 | Nov 23 |
| 1957 | Apr 16 | Nov 10 | Mar 11 | Nov 11 |
| 1956 | no data | Oct 11 | no data | Nov 10 |
| 1955 | Mar 31 | Nov 9 | Mar 29 | Nov 28 |
| 1954 | Apr 4 | Nov 1 | Apr 4 | Nov 7 |
| 1953 | Apr 21 | Oct 14 | Mar 21 | Nov 6 |
| 1952 | Mar 30 | Oct 20 | Mar 18 | 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.