Groton, CT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Groton, a city in New London County, Connecticut.
This Afternoon
66°F
Partly Sunny
Partly sunny. High near 66, with temperatures falling to around 63 in the afternoon. Southwest wind around 7 mph.
7-day forecast for Groton
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 66°F | Partly Sunny | 7 mph SW | 0% |
| Tonight | 56°F | Partly Cloudy then Patchy Fog | 7 mph SW | 3% |
| Wednesday | 68°F | Patchy Fog then Sunny | 6 to 12 mph SW | 4% |
| Wednesday Night | 60°F | Partly Cloudy | 9 mph SW | 2% |
| Thursday | 68°F | Mostly Cloudy then Slight Chance Rain Showers | 7 to 13 mph SW | 18% |
| Thursday Night | 63°F | Rain Showers | 12 mph SW | 83% |
| Friday | 66°F | Showers And Thunderstorms | 10 mph S | 93% |
| Friday Night | 57°F | Showers And Thunderstorms then Light Rain | 7 mph SW | 93% |
| Saturday | 64°F | Light Rain Likely | 10 mph NW | 71% |
| Saturday Night | 46°F | Chance Light Rain | 10 mph NW | 36% |
| Sunday | 60°F | Slight Chance Light Rain then Mostly Sunny | 12 mph W | 20% |
| Sunday Night | 42°F | Partly Cloudy then Slight Chance Light Rain | 8 to 12 mph W | 16% |
| Monday | 58°F | Chance Light Rain | 12 to 17 mph NW | 30% |
| Monday Night | 42°F | Chance Light Rain | 15 mph W | 30% |
Forecast source: National Weather Service (api.weather.gov) for Groton (41.325, -72.067). Updated through the day.
Growing snapshot for Groton
Last spring frost
Apr 8
First fall frost
Nov 2
Growing season
207 days
Hardiness zone
7a
More local growing data for Groton: nearby ZIP 06340 weather · frost dates · planting calendar · Connecticut frost dates
Nearby towns & communities
Baltic
Colchester
Conning Towers-Nautilus Park
Gales Ferry
Groton Long Point
Jewett City
Long Hill
Mashantucket
Mystic
New London
Niantic
Noank
Norwich
Old Mystic
Oxoboxo River
Pawcatuck
Poquonock Bridge
Stonington
Waterford
Climate data from the nearest NOAA station, Groton, Ct (0.3 mi from Groton). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.