Frost Dates for 06825 — Fairfield, Connecticut

Half of springs at Bridgeport Sikorsky Mem Airport, CT see their last 32°F night by April 5; only one in ten is past it by March 25, and one in ten still has one after April 17. Planting tender crops after April 9 leaves a 30% risk of a frost on them, after April 13 20%, and after April 17 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 96% of the 28 Connecticut stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 6 in half of years, as early as October 25 one year in ten, and holds off past November 20 one year in ten. A hard freeze of 28°F follows 13 days later, around November 19; in spring the one-in-ten date for 28°F is April 6, 11 days before the 32°F one. The freeze-free season lasts 216 days in a typical year, longer than at 96% of the 28 Connecticut stations; it reaches 234 days one year in ten and falls short of 198 one year in ten. On average 92 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 April 16, and return around October 26. Severe cold of 16°F or below comes every winter, usually between December 29 and February 24.

July is the warmest month at Bridgeport Sikorsky Mem Airport, CT, averaging 83°F by day and 68°F at night; January is the coldest at 38°F and 24°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 72% of years.

Warmth for growing adds up to 3,347 growing degree days a year (base 50°F), the most of the 28 Connecticut stations. 30% of them (995) have built up by the end of June, and July adds the most, 795. Precipitation totals 44.2 inches a year, most in April (4.2") and least in February (3.1"); May to September bring 42% of it.

The nearest other station, Ansonia 1 NE, CT, 13 miles northeast of Fairfield, has a last frost 20 days later (April 25), a first frost 20 days earlier (October 17), a season 41 days shorter.

The first measurable snow (0.1 inch or more) in Fairfield usually arrives around December 5, and the last of the season around March 20. Those are the middle dates across the winters of 1991–2020 at Bridgeport Sikorsky Mem Airport, CT, 6.1 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 16 days after the last snow.

ZIP 06825 is 6 miles from Bridgeport Sikorsky Mem Airport, CT, which stands at 5 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 14 other ZIP codes share the station; its figures are presented in full for 06606 (Bridgeport). The 2023 USDA Plant Hardiness Zone Map lists ZIP 06825 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.