Frost Dates for 04917 — Belgrade, Maine

Half of springs at Waterville Trtmt Plt, ME see their last 32°F night by May 2; only one in ten is past it by April 23, and one in ten still has one after May 14. Planting tender crops after May 7 leaves a 30% risk of a frost on them, after May 10 20%, and after May 14 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 67% of the 52 Maine stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 10 in half of years, as early as September 30 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 14 days later, around October 24; in spring the one-in-ten date for 28°F is May 3, 11 days before the 32°F one. The freeze-free season lasts 159 days in a typical year, longer than at 69% of the 52 Maine stations; it reaches 176 days one year in ten and falls short of 141 one year in ten. On average 164 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 12 days longer, to about May 14, and return around October 1. Severe cold of 16°F or below comes every winter, usually between November 26 and March 25.

July is the warmest month at Waterville Trtmt Plt, ME, averaging 80°F by day and 59°F at night; January is the coldest at 29°F and 9°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 60% of years.

Warmth for growing adds up to 2,201 growing degree days a year (base 50°F), more than at 75% of the 52 Maine stations. 28% of them (617) have built up by the end of June, and July adds the most, 608. Precipitation totals 43.3 inches a year, most in October (4.9") and least in February (2.6"); May to September bring 41% of it.

The nearest other station, Augusta State Airport, ME, 12 miles south of Belgrade and 277 feet higher, has a last frost 5 days earlier (April 27), a first frost 6 days later (October 16), a season 13 days longer.

The first measurable snow (0.1 inch or more) in Belgrade usually arrives around November 26, and the last of the season around April 3. Those are the middle dates across the winters of 1991–2020 at Waterville Trtmt Plt, ME, 9.1 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 29 days after the last snow.

ZIP 04917 is 9 miles from Waterville Trtmt Plt, ME, which stands at 73 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 7 other ZIP codes share the station; its figures are presented in full for 04901 (Waterville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 04917 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.