Norristown, PA 19401 Frost Dates
19401, near Norristown, PA: the frost window
The last spring frost here typically falls around 04/08, about 223 days from today. Fall's first freeze usually shows up around 10/31, roughly 203 days after the last spring frost.
Norristown sits in USDA Zone 7a (0 to 5°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Norristown's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Norristown's last frost
04/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/23 and only about 1 year in 10 sees frost after that.
Norristown against the rest of the dataset
Norristown's growing season runs about 203 days, ranking 16,845 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 188 of 2,088.
Learn more
Two guides worth reading on 19401: the frost range, on how to read the range around Norristown's dates instead of trusting one, and local microclimates, on what one yard in Norristown can differ from the 19401 normal.