Butler, PA 16045 Frost Dates
16045, near Butler, PA: the frost window
Typically, the last spring freeze lands around 04/16, roughly 231 days out. Fall's first freeze usually shows up around 11/02, roughly 199 days after the last spring frost.
Butler sits in USDA Zone 6b (-5 to 0°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
Butler'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.
Why 04/16 isn't a guarantee
04/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/31 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/02 and only about 1 year in 10 sees frost after that.
Butler against the rest of the dataset
Butler's growing season runs about 199 days, ranking 18,061 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 290 of 2,088.
Learn more
Two guides worth reading on 16045: zone vs. frost date, on why Zone 6b and Butler's frost date answer different questions, and the frost range, on how to read the range around Butler's dates instead of trusting one.