Frost Dates for 05443 — Bristol, Vermont

Half of springs at S Lincoln, VT see their last 32°F night by May 21; only one in ten is past it by May 6, and one in ten still has one after June 6. Planting tender crops after May 28 leaves a 30% risk of a frost on them, after June 1 20%, and after June 6 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 September 25 in half of years, as early as September 8 one year in ten, and holds off past October 7 one year in ten. A hard freeze of 28°F follows 10 days later, around October 5; in spring the one-in-ten date for 28°F is May 23, 14 days before the 32°F one. The freeze-free season lasts 124 days in a typical year, shorter than at 95% of the 41 Vermont stations; it reaches 146 days one year in ten and falls short of 103 one year in ten. On average 178 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 June 4, and return around September 12. Severe cold of 16°F or below comes every winter, usually between November 11 and April 6.

July is the warmest month at S Lincoln, VT, averaging 76°F by day and 54°F at night; January is the coldest at 26°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 20% of years.

Warmth for growing adds up to 1,588 growing degree days a year (base 50°F), fewer than at 95% of the 41 Vermont stations. 30% of them (476) have built up by the end of June, and July adds the most, 456. Precipitation totals 49.5 inches a year, most in July (5.3") and least in February (2.5"); May to September bring 49% of it.

The nearest other station, Vergennes, VT, 10 miles west of Bristol and 1,145 feet lower, has a last frost 21 days earlier (April 30), a first frost 22 days later (October 17), a season 44 days longer.

The first measurable snow (0.1 inch or more) in Bristol usually arrives around October 31, and the last of the season around April 16. Those are the middle dates across the winters of 1991–2020 at S Lincoln, VT, 5.5 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 05443 is 6 miles from S Lincoln, VT, which stands at 1,341 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 05443 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.