Frost Dates for 06029 — Ellington, Connecticut

Half of springs at Staffordville, CT see their last 32°F night by May 7; 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 13 leaves a 30% risk of a frost on them, after May 17 20%, and after May 21 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 12 in half of years, as early as October 1 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 12 days later, around October 24; in spring the one-in-ten date for 28°F is May 11, 10 days before the 32°F one. The freeze-free season lasts 159 days in a typical year, shorter than at 93% of the 28 Connecticut stations; it reaches 178 days one year in ten and falls short of 140 one year in ten. On average 152 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 12 days longer, to about May 19, and return around October 3. Severe cold of 16°F or below comes every winter, usually between November 29 and March 21.

July is the warmest month at Staffordville, CT, averaging 81°F by day and 59°F at night; January is the coldest at 34°F and 14°F. A freezing night is all but certain in every month from October 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 72% of years.

Warmth for growing adds up to 2,310 growing degree days a year (base 50°F), fewer than at 96% of the 28 Connecticut stations. 29% of them (666) have built up by the end of June, and July adds the most, 611. Precipitation totals 50.4 inches a year, most in October (4.9") and least in February (3.3"); May to September bring 42% of it.

The nearest other station, Hartford Bradley International Airport, CT, 12 miles west of Ellington and 546 feet lower, has a last frost 16 days earlier (April 21), a first frost 4 days later (October 16), a season 18 days longer.

The first measurable snow (0.1 inch or more) in Ellington usually arrives around December 2, and the last of the season around March 31. Those are the middle dates across the winters of 1991–2020 at Hartford Bradley International Airport, CT, 12.1 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 37 days after the last snow.

ZIP 06029 is 12 miles from Staffordville, CT, which stands at 736 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 06029 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.