Frost dates in Connecticut

Across Connecticut's 23 NOAA stations with a frost every year, the typical last spring frost ranges from April 5 at Bridgeport Sikorsky Mem Airport (at sea level) to May 11 at Falls Village (550 feet above sea level). The middle station's date is April 25.

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Last frost across Connecticut

The frost-free season runs from 146 days at Falls Village to 216 days at Bridgeport Sikorsky Mem Airport.

These are typical dates: in half of springs the last frost comes later. Each place's page, and each ZIP code lookup, also gives the late-year date, after which only 1 spring in 10 has a frost. That's the safer date for tender plants.

Frost dates for Connecticut's larger places

PlaceLast spring frostFirst fall frostSeasonZone
BridgeportApril 5November 6216 days7a
HartfordApril 17October 26191 days6b
New HavenApril 17October 27193 days7a
StamfordApril 17October 23188 days7a
WaterburyApril 26October 16175 days6b

Typical (1-in-2) dates. Each place's page has the early and late years, a planting calendar and a printable planner. Zones are for the ZIP code nearest each place's center.

Hardiness zones in Connecticut

Connecticut's 418 ZIP codes in the USDA list fall in zones 6a to 7b: 6a (12 percent), 6b (60 percent), 7a (27 percent) and 7b (1 percent). Compared with the 2012 map, 46 percent of them moved to a warmer half zone and 54 percent stayed the same.

A hardiness zone is about the coldest night of winter, which decides which shrubs, trees and perennials survive. Frost dates are about spring and fall, which decide when to plant. You need both. Read more about what the zones mean and what changed in 2023.

Every NOAA station in Connecticut

All 23 stations in Connecticut with frost statistics in NOAA's 1991 to 2020 normals, from A to Z. Station names are usually a town, an airport, or a distance and direction from a town. Find one near you and at a similar elevation.

StationElevation (feet)Last spring frostFirst fall frostSeason (days)
Ansonia 1 NE140April 25October 17175
Bakersville690May 8October 5151
Barkhamsted710April 30October 17168
Bridgeport Sikorsky Mem Airport10April 5November 6216
Burlington510April 25October 18172
Danbury400April 20October 20181
Danbury Municipal Airport460May 1October 14166
Falls Village550May 11October 4146
Groton40April 8November 2207
Groton New London Airport10April 16October 28194
Hampton490April 30October 15167
Hartford Bradley International Airport190April 21October 16177
Hartford Brainard Field20April 17October 26191
Meriden Markham Municipal Airport100April 26October 16175
Mount Carmel180April 18October 26191
New Haven Tweed Airport0April 17October 27193
Norfolk 2 SW1,340May 3October 11161
Norwich Public Utility Plant20April 14October 24192
Staffordville730May 7October 12159
Stamford 5 N190April 17October 23188
Storrs670April 19October 22186
W Thompson Lake360May 1October 9161
Willimantic Windham Airport250April 28October 13167

Typical (1-in-2) dates at 32°F. For the early and late years, and a planting calendar built from your own dates, look up your ZIP code.