Smithfield, PA 15478 Frost Dates
Smithfield, PA: when does the frost end?
Typically, the last spring freeze lands around 04/28, roughly 243 days out. Fall's first freeze usually shows up around 10/21, roughly 175 days after the last spring frost.
Smithfield 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
With roughly 8 weeks until Smithfield's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
04/28 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/15 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/14 and only about 1 year in 10 sees frost after that.
Smithfield against the rest of the dataset
About 175 days separate Smithfield's last and first frost, putting it 27,118 of 40,283 ZIP codes nationally. Within PA, it ranks 1,231 of 2,088.
Learn more
Before leaning on 15478's figures: the frost range explains how to read the range around Smithfield's dates instead of trusting one, while local microclimates explains what one yard in Smithfield can differ from the 15478 normal.