Connecticut frost dates: Last spring and first autumn frost at every NOAA station, 1991-2020
Across Connecticut's 23 NOAA stations with frost dates, the median last spring frost (32°F) runs from April 5 in Bridgeport to May 11 in Falls Village; for half of its places it comes after April 21.
- Typical last spring frost
- April 21median of 13 places
- Typical first autumn frost
- October 17median of 13 places
- Earliest last frost
- April 5Bridgeport
- Latest last frost
- May 11Falls Village
When is the last frost in Connecticut, town by town?
Each date is NOAA's: "after April 21 in half of years" means the last 32°F night of spring came after April 21 in half of the years 1991-2020. By the 1-in-10 date, the last frost has passed in nine years out of ten.
Find your town in the list, or look up a ZIP code for the stations nearest it.
| Place or station | Last frost (median) | 1 in 10 after | First frost (median) | 1 in 10 before | Growing season | Zone |
|---|---|---|---|---|---|---|
| BridgeportIgor I Sikorsky Memorial Airport | April 5 | April 17 | November 6 | October 25 | 216 days | 7a |
| Groton station | April 8 | April 22 | November 2 | October 18 | 207 days | 7a |
| NorwichNorwich Public Utility Plant | April 14 | April 30 | October 24 | October 9 | 192 days | 7a |
| GrotonGroton New London Airport | April 16 | April 30 | October 28 | October 13 | 194 days | 7a |
| Hartford Brainard Field | April 17 | May 1 | October 26 | October 12 | 191 days | 7a |
| New HavenNew Haven Tweed Airport | April 17 | May 1 | October 27 | October 11 | 193 days | 7a |
| Stamford5 mi N | April 17 | May 2 | October 23 | October 8 | 188 days | 6b |
| Mount Carmel | April 18 | May 3 | October 26 | October 11 | 191 days | 6b |
| Storrs | April 19 | May 3 | October 22 | October 6 | 186 days | 6b |
| Danbury station | April 20 | May 6 | October 20 | October 5 | 181 days | 6b |
| HartfordHartford-Bradley International Airport | April 21 | May 6 | October 16 | October 3 | 177 days | 6b |
| Ansonia1 mi NE | April 25 | May 10 | October 17 | October 4 | 175 days | – |
| Burlington | April 25 | May 10 | October 18 | October 4 | 172 days | 6b |
| MeridenMeriden Markham Municipal Airport | April 26 | May 9 | October 16 | October 4 | 175 days | 6b |
| WillimanticWillimantic Windham Airport | April 28 | May 11 | October 13 | October 2 | 167 days | 6b |
| Barkhamsted | April 30 | May 15 | October 17 | October 4 | 168 days | – |
| Hampton | April 30 | May 11 | October 15 | October 1 | 167 days | – |
| DanburyDanbury Municipal Airport | May 1 | May 16 | October 14 | October 1 | 166 days | 6b |
| West Thompson Lake | May 1 | May 17 | October 9 | September 30 | 161 days | 6a |
| Norfolk2 mi SW | May 3 | May 17 | October 11 | October 1 | 161 days | 6a |
| Staffordville | May 7 | May 21 | October 12 | October 1 | 159 days | 6a |
| Bakersville | May 8 | May 22 | October 5 | September 25 | 151 days | 6a |
| Falls Village | May 11 | May 27 | October 4 | September 21 | 146 days | 6a |
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities, growing-season length); station daily lows via ACIS (zone). Growing season: NOAA's median number of days between the last spring and first autumn 32°F night. Zone: the USDA's plant hardiness rule applied to the station's own 1991-2020 coldest nights.