Frost Dates for 06018 — Canaan, Connecticut

Half of springs at Norfolk 2 SW, CT see their last 32°F night by May 3; only one in ten is past it by April 21, and one in ten still has one after May 17. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 13 20%, and after May 17 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 11 in half of years, as early as October 1 one year in ten, and holds off past October 28 one year in ten. A hard freeze of 28°F follows 14 days later, around October 25; in spring the one-in-ten date for 28°F is May 6, 11 days before the 32°F one. The freeze-free season lasts 161 days in a typical year, shorter than at 86% of the 28 Connecticut stations; it reaches 181 days one year in ten and falls short of 144 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 15, and return around October 2. Severe cold of 16°F or below comes every winter, usually between November 27 and March 22.

July is the warmest month at Norfolk 2 SW, CT, averaging 78°F by day and 60°F at night; January is the coldest at 30°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 62% of years.

Warmth for growing adds up to 2,192 growing degree days a year (base 50°F), the fewest of the 28 Connecticut stations. 31% of them (675) have built up by the end of June, and July adds the most, 587. Precipitation totals 53.0 inches a year, most in October (5.1") and least in February (3.3"); May to September bring 44% of it.

The nearest other station, Falls Village, CT, 6 miles southwest of Canaan and 790 feet lower, has a last frost 8 days later (May 11), a first frost 7 days earlier (October 4), a season 15 days shorter.

The first measurable snow (0.1 inch or more) in Canaan usually arrives around November 12, and the last of the season around April 8. Those are the middle dates across the winters of 1991–2020 at Norfolk 2 SW, CT, 5.8 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 25 days after the last snow.

ZIP 06018 is 6 miles from Norfolk 2 SW, CT, which stands at 1,340 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 06756 (Goshen). The 2023 USDA Plant Hardiness Zone Map lists ZIP 06018 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.