Frost Dates for 04294 — Wilton, Maine

Half of springs at Farmington, ME see their last 32°F night by May 16; only one in ten is past it by May 3, and one in ten still has one after June 1. Planting tender crops after May 22 leaves a 30% risk of a frost on them, after May 25 20%, and after June 1 10%. The 16 days between the even-odds date and the one-in-ten date is wider than at 94% of the 52 Maine stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 26 in half of years, as early as September 14 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 5; in spring the one-in-ten date for 28°F is May 19, 13 days before the 32°F one. The freeze-free season lasts 130 days in a typical year, shorter than at 92% of the 52 Maine stations; it reaches 149 days one year in ten and falls short of 110 one year in ten. On average 183 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 14 days longer, to about May 30, and return around September 16. Severe cold of 16°F or below comes every winter, usually between November 15 and April 1.

July is the warmest month at Farmington, ME, averaging 79°F by day and 56°F at night; January is the coldest at 27°F and 6°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 10% of years.

Warmth for growing adds up to 1,832 growing degree days a year (base 50°F), fewer than at 81% of the 52 Maine stations. 29% of them (525) have built up by the end of June, and July adds the most, 529. Precipitation totals 49.5 inches a year, most in October (5.2") and least in February (3.2"); May to September bring 42% of it.

The nearest other station, Livermore Falls 1 E, ME, 10 miles south of Wilton, has a last frost 5 days earlier (May 11), a first frost 3 days later (September 29), a season 8 days longer.

The first measurable snow (0.1 inch or more) in Wilton usually arrives around November 13, and the last of the season around April 11. Those are the middle dates across the winters of 1991–2020 at Farmington, ME, 7 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 35 days after the last snow.

ZIP 04294 is 7 miles from Farmington, ME, which stands at 405 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 04938 (Farmington). The 2023 USDA Plant Hardiness Zone Map lists ZIP 04294 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.