Slippery Rock, PA 16057 Frost Dates
When can you plant in Slippery Rock, PA?
The last spring frost here typically falls around 05/15, about 260 days from today. The first fall frost typically arrives around 10/03, about 140 frost-free days later.
The USDA Plant Hardiness Zone Map puts Slippery Rock in Zone 6a (-10 to -5°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 5 weeks of growing season left in Slippery Rock before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Slippery Rock's last frost
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 06/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Slippery Rock compares
Slippery Rock's growing season runs about 140 days, ranking 37,054 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 1,983 of 2,088.
Learn more
zone vs. frost date covers why Zone 6a and Slippery Rock's frost date answer different questions. the frost range covers how to read the range around Slippery Rock's dates instead of trusting one.