Frost Dates for 05602 — Montpelier, Vermont

Half of springs at Montpelier 2, VT see their last 32°F night by May 5; only one in ten is past it by April 23, and one in ten still has one after May 21. Planting tender crops after May 12 leaves a 30% risk of a frost on them, after May 16 20%, and after May 21 10%. The 16 days between the even-odds date and the one-in-ten date is wider than at 78% of the 41 Vermont stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 9 in half of years, as early as September 28 one year in ten, and holds off past October 24 one year in ten. A hard freeze of 28°F follows 12 days later, around October 21; in spring the one-in-ten date for 28°F is May 8, 13 days before the 32°F one. The freeze-free season lasts 157 days in a typical year, longer than at 78% of the 41 Vermont stations; it reaches 174 days one year in ten and falls short of 138 one year in ten. On average 168 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 18, and return around October 1. Severe cold of 16°F or below comes every winter, usually between November 23 and March 30.

July is the warmest month at Montpelier 2, VT, averaging 82°F by day and 59°F at night; January is the coldest at 28°F and 7°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 65% of years.

Warmth for growing adds up to 2,349 growing degree days a year (base 50°F), more than at 76% of the 41 Vermont stations. 31% of them (718) have built up by the end of June, and July adds the most, 628. Precipitation totals 41.4 inches a year, most in July (4.6") and least in February (2.4"); May to September bring 49% of it.

The nearest other station, Barre Montpelier Airport, VT, 4 miles south of Montpelier and 596 feet higher, has a last frost 11 days later (May 16), a first frost 10 days earlier (September 29), a season 21 days shorter.

The first measurable snow (0.1 inch or more) in Montpelier usually arrives around November 18, and the last of the season around March 30. Those are the middle dates across the winters of 1991–2020 at Montpelier 2, VT, 0.7 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 36 days after the last snow.

ZIP 05602 is under a mile from Montpelier 2, VT, which stands at 530 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 05602 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.