Connecticut frost dates

Average last spring and first fall frost dates for Connecticut’s largest cities, with each city’s USDA hardiness zone.

Reviewed October 2026

Among Connecticut’s 20 largest cities, the average last spring frost ranges from Apr 5 in Bridgeport to May 8 in Torrington. Elevation, distance from the coast and city heat all shift the date, so use your own ZIP code below for the closest match.

City	Average last spring frost	Average first fall frost	Frost-free days	Hardiness zone	Weather station used
Bridgeport	Apr 5	Nov 6	215	7a	Bridgeport Sikorsky Mem Airport, CT, 4 mi
Stamford	Apr 17	Oct 23	189	7a–7b	Stamford 5 N, CT, 3 mi
New Haven	Apr 17	Oct 27	193	6b–7a	New Haven Tweed Airport, CT, 4 mi
Hartford	Apr 17	Oct 26	192	6b	Hartford Brainard Fld, CT, 3 mi
Waterbury	Apr 26	Oct 16	173	6b	Meriden Markham Muni Airport, CT, 11 mi
Norwalk	Apr 17	Oct 23	189	7a–7b	Stamford 5 N, CT, 7 mi
Danbury	May 1	Oct 14	166	6b	Danbury Muni Airport, CT, 2 mi
New Britain	Apr 17	Oct 26	192	6b	Hartford Brainard Fld, CT, 8 mi
Bristol	Apr 25	Oct 18	176	6a–6b	Burlington, CT, 8 mi
Meriden	Apr 26	Oct 16	173	6b	Meriden Markham Muni Airport, CT, 3 mi
West Haven	Apr 17	Oct 27	193	7a	New Haven Tweed Airport, CT, 4 mi
Milford	Apr 5	Nov 6	215	7a	Bridgeport Sikorsky Mem Airport, CT, 6 mi
Middletown	Apr 26	Oct 16	173	6b	Meriden Markham Muni Airport, CT, 9 mi
Shelton	Apr 25	Oct 17	175	6b–7a	Ansonia 1 Ne, CT, 4 mi
Norwich	Apr 14	Oct 24	193	6b	Norwich Public Utility Plt, CT, 2 mi
Torrington	May 8	Oct 5	150	6a	Bakersville, CT, 6 mi
Naugatuck	Apr 18	Oct 26	191	6b	Mt Carmel, CT, 9 mi
New London	Apr 16	Oct 28	195	7a	Groton New London Airport, CT, 2 mi
Ansonia	Apr 25	Oct 17	175	6b–7a	Ansonia 1 Ne, CT
Derby	Apr 25	Oct 17	175	6b–7a	Ansonia 1 Ne, CT, 2 mi

Frost dates are the dates after (spring) or before (fall) which the chance of a 32°F freeze is below 50%, from NOAA’s 1991–2020 U.S. Climate Normals for the weather station nearest each city’s center. Zones are from the 2023 USDA Plant Hardiness Zone Map for the ZIP codes around each city; a range means nearby ZIP codes differ. Cities are the 20 largest by Census Bureau 2024 population estimates.

An average is not a guarantee. There’s still about a 1 in 2 chance of frost after the average last spring date. Many gardeners wait an extra week or two before setting out tomatoes, peppers and basil, and keep covers handy.

Planting dates for Bridgeport

Timed from Bridgeport’s average last frost of Apr 5, using University of New Hampshire Extension’s planting guidance. For your exact dates, enter your ZIP code in the calendar below.

Crop	Start seeds indoors	Plant outside
Tomatoes	Feb 15 to Mar 1	Apr 12 to Apr 19
Peppers	Feb 8 to Feb 22	Apr 19
Lettuce	Feb 1 to Feb 8	Mar 8 to Mar 15
Broccoli	Jan 25 to Feb 8	Mar 8 to Mar 22
Cucumbers	Mar 15 to Mar 22	Apr 12 to Apr 19
Basil	Feb 22 to Mar 8	Apr 19

When to plant, for your garden

Your seed-starting and planting dates, timed from your last spring frost. Full calendar, 12 crops.

ZIP code

Last frost date

Enter your ZIP code to look up your average last frost date and hardiness zone, or type the date in yourself.

Frost dates: NOAA U.S. Climate Normals, 1991–2020. Hardiness zones: USDA Plant Hardiness Zone Map, 2023, ZIP code data from PRISM Group, Oregon State University, prism.oregonstate.edu, accessed Oct. 20, 2026.

More about frost dates

How to find your last frost date, and what your zone means · Full planting calendar · How to start seeds indoors

Other states

Alabama · Alaska · Arizona · Arkansas · California · Colorado · Delaware · District of Columbia · Florida · Georgia · Hawaii · Idaho · Illinois · Indiana · Iowa · Kansas · Kentucky · Louisiana · Maine · Maryland · Massachusetts · Michigan · Minnesota · Mississippi · Missouri · Montana · Nebraska · Nevada · New Hampshire · New Jersey · New Mexico · New York · North Carolina · North Dakota · Ohio · Oklahoma · Oregon · Pennsylvania · Rhode Island · South Carolina · South Dakota · Tennessee · Texas · Utah · Vermont · Virginia · Washington · West Virginia · Wisconsin · Wyoming