Frost Dates for 06751 — Bethlehem, Connecticut

Half of springs at Bakersville, CT see their last 32°F night by May 8; only one in ten is past it by April 24, and one in ten still has one after May 22. Planting tender crops after May 14 leaves a 30% risk of a frost on them, after May 18 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 28 Connecticut stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 5 in half of years, as early as September 25 one year in ten, and holds off past October 21 one year in ten. A hard freeze of 28°F follows 13 days later, around October 18; in spring the one-in-ten date for 28°F is May 11, 11 days before the 32°F one. The freeze-free season lasts 151 days in a typical year, shorter than at 96% of the 28 Connecticut stations; it reaches 171 days one year in ten and falls short of 132 one year in ten. On average 158 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 11 days longer, to about May 19, and return around September 27. Severe cold of 16°F or below comes every winter, usually between November 26 and March 20.

July is the warmest month at Bakersville, CT, averaging 82°F by day and 58°F at night; January is the coldest at 33°F and 15°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 73% of years.

Warmth for growing adds up to 2,345 growing degree days a year (base 50°F), fewer than at 93% of the 28 Connecticut stations. 32% of them (743) have built up by the end of June, and July adds the most, 618. Precipitation totals 54.3 inches a year, most in October (5.4") and least in February (3.5"); May to September bring 43% of it.

The nearest other station, Burlington, CT, 18 miles northeast of Bethlehem and 181 feet lower, has a last frost 13 days earlier (April 25), a first frost 13 days later (October 18), a season 21 days longer.

The first measurable snow (0.1 inch or more) in Bethlehem usually arrives around November 30, and the last of the season around March 25. Those are the middle dates across the winters of 1991–2020 at Woodbury, CT, 6 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 44 days after the last snow.

ZIP 06751 is 17 miles from Bakersville, CT, which stands at 686 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 06790 (Torrington). The 2023 USDA Plant Hardiness Zone Map lists ZIP 06751 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.