Keene, NH 03452 Frost Dates
Frost dates for Keene, NH, ZIP 03452
Around 05/05 is the usual last spring frost, about 250 days away. The first fall frost typically arrives around 10/06, about 154 frost-free days later.
The USDA Plant Hardiness Zone Map puts Keene 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
Zone 6a around Keene has about 6 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.
How much risk comes with planting early here
05/05 is the middle of 30 years of NOAA records, not a promise. Plant by 04/22 and you're betting against frost in roughly 9 years out of 10. 05/19 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Keene compares
Keene's growing season runs about 154 days, ranking 34,220 of 40,283 US ZIP codes measured here, longest to shortest. Within NH, it ranks 108 of 260.
Learn more
the frost range explains how to read the range around Keene's dates instead of trusting one, and local microclimates explains what one yard in Keene can differ from the 03452 normal.