Keene, NH 03431 Frost Dates
Keene, NH: when does the frost end?
Typically, the last spring freeze lands around 05/14, roughly 259 days out. Fall's first freeze usually shows up around 10/01, roughly 138 days after the last spring frost.
Keene sits in USDA Zone 5b (-15 to -10°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 5 weeks until Keene's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Keene's last frost
05/14 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/30 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/28 and only about 1 year in 10 sees frost after that.
Keene against the rest of the dataset
At roughly 138 frost-free days, Keene places 37,340 of 40,283 ZIP codes in this dataset. Within NH, it ranks 192 of 260.
Learn more
Before leaning on 03431's figures: zone vs. frost date explains why Zone 5b and Keene's frost date answer different questions, while the frost range explains how to read the range around Keene's dates instead of trusting one.