Frost Dates for 04930 — Dexter, Maine

Half of springs at Corinna, ME see their last 32°F night by May 8; only one in ten is past it by April 27, and one in ten still has one after May 23. Planting tender crops after May 14 leaves a 30% risk of a frost on them, after May 18 20%, and after May 23 10%. The 15 days between the even-odds date and the one-in-ten date is wider than at 83% of the 52 Maine stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 3 in half of years, as early as September 21 one year in ten, and holds off past October 17 one year in ten. A hard freeze of 28°F follows 12 days later, around October 15; in spring the one-in-ten date for 28°F is May 8, 15 days before the 32°F one. The freeze-free season lasts 148 days in a typical year, shorter than at 58% of the 52 Maine stations; it reaches 164 days one year in ten and falls short of 129 one year in ten. On average 175 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 13 days longer, to about May 21, and return around September 23. Severe cold of 16°F or below comes every winter, usually between November 22 and March 31.

July is the warmest month at Corinna, ME, averaging 81°F by day and 58°F at night; January is the coldest at 28°F and 6°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 78% of years.

Warmth for growing adds up to 2,146 growing degree days a year (base 50°F), more than at 69% of the 52 Maine stations. 29% of them (622) have built up by the end of June, and July adds the most, 597. Precipitation totals 44.6 inches a year, most in October (4.8") and least in February (2.8"); May to September bring 40% of it.

The nearest other station, Dover-Foxcroft Wwtp, ME, 13 miles northeast of Dexter, has a last frost 7 days later (May 15), a first frost 5 days earlier (September 28), a season 14 days shorter.

The first measurable snow (0.1 inch or more) in Dexter usually arrives around November 23, and the last of the season around April 5. Those are the middle dates across the winters of 1991–2020 at Corinna, ME, 7.7 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 33 days after the last snow.

ZIP 04930 is 8 miles from Corinna, ME, which stands at 297 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 04930 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.