FrostDateCheck

Keene, NH 03465 Frost Dates

When can you plant in Keene, NH?

Zone 6a

Typically, the last spring freeze lands around 05/05, roughly 250 days out. 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

About 6 weeks of growing season left in Keene before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

Why 05/05 isn't a guarantee

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 34,222 of 40,283 US ZIP codes measured here, longest to shortest. Within NH, it ranks 110 of 260.

Learn more

local microclimates covers what one yard in Keene can differ from the 03465 normal. zone vs. frost date covers why Zone 6a and Keene's frost date answer different questions.