Frost Dates for 06238 — Coventry, Connecticut

Half of springs at Storrs, CT see their last 32°F night by April 19; only one in ten is past it by April 7, and one in ten still has one after May 3. Planting tender crops after April 25 leaves a 30% risk of a frost on them, after April 29 20%, and after May 3 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 22 in half of years, as early as October 6 one year in ten, and holds off past November 6 one year in ten. A hard freeze of 28°F follows 13 days later, around November 4; in spring the one-in-ten date for 28°F is April 19, 14 days before the 32°F one. The freeze-free season lasts 186 days in a typical year, longer than at 61% of the 28 Connecticut stations; it reaches 205 days one year in ten and falls short of 165 one year in ten. On average 123 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 May 3, and return around October 10. Severe cold of 16°F or below comes every winter, usually between December 9 and March 11.

July is the warmest month at Storrs, CT, averaging 81°F by day and 63°F at night; January is the coldest at 35°F and 19°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 15% of years.

Warmth for growing adds up to 2,683 growing degree days a year (base 50°F), fewer than at 68% of the 28 Connecticut stations. 31% of them (823) have built up by the end of June, and July adds the most, 671. Precipitation totals 49.3 inches a year, most in October (4.6") and least in February (3.0"); May to September bring 43% of it.

The nearest other station, Willimantic Windham Airport, CT, 8 miles east of Coventry and 418 feet lower, has a last frost 9 days later (April 28), a first frost 9 days earlier (October 13), a season 19 days shorter.

The first measurable snow (0.1 inch or more) in Coventry usually arrives around December 5, and the last of the season around March 23. Those are the middle dates across the winters of 1991–2020 at Storrs, CT, 5.4 miles away: half of years saw snow earlier, half later. Snow fell in 92% of those winters. The last 32°F night of spring typically comes 27 days after the last snow.

ZIP 06238 is 5 miles from Storrs, CT, which stands at 665 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 06084 (Tolland). The 2023 USDA Plant Hardiness Zone Map lists ZIP 06238 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.