Altoona, PA 16602 Frost Dates
Frost dates for Altoona, PA, ZIP 16602
Around 04/23 is the usual last spring frost, about 238 days away. The first fall frost typically arrives around 10/21, about 177 frost-free days later.
The USDA Plant Hardiness Zone Map puts Altoona in Zone 6b (-5 to 0°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
Zone 6b around Altoona has about 8 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 04/23 isn't a guarantee
04/23 is the middle of 30 years of NOAA records, not a promise. Plant by 04/08 and you're betting against frost in roughly 9 years out of 10. 05/11 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Altoona compares
Altoona's growing season runs about 177 days, ranking 26,011 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 942 of 2,088.
Learn more
local microclimates explains what one yard in Altoona can differ from the 16602 normal, and zone vs. frost date explains why Zone 6b and Altoona's frost date answer different questions.