Frost Dates for 03785 — Woodsville, New Hampshire

Half of springs at Benton 5 SW, NH see their last 32°F night by May 15; only one in ten is past it by May 1, and one in ten still has one after June 3. Planting tender crops after May 22 leaves a 30% risk of a frost on them, after May 26 20%, and after June 3 10%. The 19 days between the even-odds date and the one-in-ten date is the widest of the 51 New Hampshire stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 28 in half of years, as early as September 12 one year in ten, and holds off past October 9 one year in ten. A hard freeze of 28°F follows 9 days later, around October 7; in spring the one-in-ten date for 28°F is May 16, 18 days before the 32°F one. The freeze-free season lasts 133 days in a typical year, shorter than at 82% of the 51 New Hampshire stations; it reaches 154 days one year in ten and falls short of 110 one year in ten. On average 173 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 16 days longer, to about May 31, and return around September 17. Severe cold of 16°F or below comes every winter, usually between November 16 and April 1.

July is the warmest month at Benton 5 SW, NH, averaging 77°F by day and 56°F at night; January is the coldest at 26°F and 7°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 88% of years and June still brings one in 14% of years.

Warmth for growing adds up to 1,791 growing degree days a year (base 50°F), fewer than at 90% of the 51 New Hampshire stations. 30% of them (533) have built up by the end of June, and July adds the most, 511. Precipitation totals 41.4 inches a year, most in October (4.5") and least in February (2.1"); May to September bring 47% of it.

The nearest other station, Wentworth, NH, 19 miles south of Woodsville and 547 feet lower, has a last frost 3 days earlier (May 12), a first frost 8 days later (October 6), a season 13 days longer.

The first measurable snow (0.1 inch or more) in Woodsville usually arrives around October 29, and the last of the season around April 19. Those are the middle dates across the winters of 1991–2020 at Benton 5 SW, NH, 6.9 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 26 days after the last snow.

ZIP 03785 is 7 miles from Benton 5 SW, NH, which stands at 1,200 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 03785 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.