Frost Dates for 05048 — Hartland, Vermont

Half of springs at N Hartland Lake, VT 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 22. Planting tender crops after May 13 leaves a 30% risk of a frost on them, after May 17 20%, and after May 22 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 54% of the 41 Vermont stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 6 in half of years, as early as September 25 one year in ten, and holds off past October 19 one year in ten. A hard freeze of 28°F follows 11 days later, around October 17; in spring the one-in-ten date for 28°F is May 8, 14 days before the 32°F one. The freeze-free season lasts 150 days in a typical year, longer than at 66% of the 41 Vermont stations; it reaches 168 days one year in ten and falls short of 131 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 13 days longer, to about May 21, and return around September 28. Severe cold of 16°F or below comes every winter, usually between November 21 and March 30.

July is the warmest month at N Hartland Lake, VT, averaging 80°F by day and 57°F at night; January is the coldest at 28°F and 8°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 80% of years.

Warmth for growing adds up to 2,083 growing degree days a year (base 50°F), fewer than at 56% of the 41 Vermont stations. 30% of them (633) have built up by the end of June, and July adds the most, 578.

The nearest other station, Lebanon Municipal Airport, NH, 6 miles northeast of Hartland, has a last frost 1 day later (May 9), the same first-frost date, a season 2 days shorter.

The first measurable snow (0.1 inch or more) in Hartland usually arrives around November 18, and the last of the season around April 5. Those are the middle dates across the winters of 1991–2020 at Woodstock, VT, 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 05048 is 3 miles from N Hartland Lake, VT, which stands at 570 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 05089 (Windsor). The 2023 USDA Plant Hardiness Zone Map lists ZIP 05048 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.