Garden Yardstick

Frost Dates in Connecticut

Across 23 NOAA weather stations in Connecticut, the average last spring frost falls between April 5 at Bridgeport Sikorsky Mem Airport and May 11 at Falls Village. At a typical Connecticut station it is around April 25, with the first fall frost around October 17 and a frost-free season of about 175 days.

Find the frost dates for your ZIP code

A typical Connecticut season

What shapes frost dates in Connecticut

  • The frost-free season ranges from 146 days at Falls Village to 216 days at Bridgeport Sikorsky Mem Airport.
  • Elevation matters: Norfolk 2 SW, at 1,340 ft, averages its last frost on May 3, while New Haven Tweed Airport, at 3 ft, averages April 17.
  • Gardens in valleys and low spots, where cold air settles, often frost a week or more later in spring than the nearest station.

Frost dates at major airports

StationLast frostSafer dateFirst frostSeason (days)
Bridgeport Sikorsky Mem AirportApr 5Apr 17Nov 6216
Danbury Muni AirportMay 1May 16Oct 14166
Groton New London AirportApr 16Apr 30Oct 28194
Hartford Bradley Intl AirportApr 21May 6Oct 16177
Hartford Brainard FldApr 17May 1Oct 26191
Meriden Markham Muni AirportApr 26May 9Oct 16175
New Haven Tweed AirportApr 17May 1Oct 27193
Willimantic Windham AirportApr 28May 11Oct 13167

All 23 weather stations in Connecticut

StationElevation (ft)Last frostSafer dateFirst frostSeason (days)
Ansonia 1 NE136Apr 25May 10Oct 17175
Bakersville686May 8May 22Oct 5151
Barkhamsted710Apr 30May 15Oct 17168
Bridgeport Sikorsky Mem Airport5Apr 5Apr 17Nov 6216
Burlington505Apr 25May 10Oct 18172
Danbury405Apr 20May 6Oct 20181
Danbury Muni Airport457May 1May 16Oct 14166
Falls Village550May 11May 27Oct 4146
Groton40Apr 8Apr 22Nov 2207
Groton New London Airport10Apr 16Apr 30Oct 28194
Hampton490Apr 30May 11Oct 15167
Hartford Bradley Intl Airport190Apr 21May 6Oct 16177
Hartford Brainard Fld19Apr 17May 1Oct 26191
Meriden Markham Muni Airport103Apr 26May 9Oct 16175
Mt Carmel180Apr 18May 3Oct 26191
New Haven Tweed Airport3Apr 17May 1Oct 27193
Norfolk 2 SW1,340May 3May 17Oct 11161
Norwich Public Utility Plt20Apr 14Apr 30Oct 24192
Staffordville736May 7May 21Oct 12159
Stamford 5 N190Apr 17May 2Oct 23188
Storrs665Apr 19May 3Oct 22186
W Thompson Lake360May 1May 17Oct 9161
Willimantic Windham Airport247Apr 28May 11Oct 13167

Last frost and first frost are averages (a 50% chance of frost later in spring or earlier in fall). Safer date is the spring date with only a 10% chance of a later frost.

Using these dates

Plant hardy crops like peas and spinach several weeks before your last frost, and tender crops like tomatoes and peppers after it, once nights stay above 50°F. The Seed Starting Calculator turns your frost date into sowing and planting dates, and When to Plant Tomatoes explains the timing in detail.

Data: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, 32°F threshold.

Frost dates in other states