Groton, CT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Groton, a city in New London County, Connecticut.
Today
77°F
Mostly Sunny
Mostly sunny, with a high near 77. Southwest wind around 6 mph.
7-day forecast for Groton
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 77°F | Mostly Sunny | 6 mph SW | 0% |
| Tonight | 65°F | Mostly Cloudy | 5 mph E | 11% |
| Wednesday | 78°F | Partly Sunny | 6 mph W | 8% |
| Wednesday Night | 70°F | Mostly Cloudy then Slight Chance Rain Showers | 5 mph S | 18% |
| Thursday | 81°F | Mostly Sunny | 5 to 12 mph SW | 13% |
| Thursday Night | 73°F | Mostly Clear | 6 to 10 mph SW | 12% |
| Friday | 82°F | Sunny | 6 to 10 mph SW | 10% |
| Friday Night | 71°F | Slight Chance Showers And Thunderstorms | 5 to 9 mph SW | 19% |
| Saturday | 82°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 to 9 mph SW | 18% |
| Saturday Night | 71°F | Slight Chance Showers And Thunderstorms | 3 to 8 mph SW | 21% |
| Sunday | 82°F | Mostly Sunny | 5 to 9 mph W | 11% |
| Sunday Night | 71°F | Mostly Clear | 5 to 8 mph SW | 7% |
| Monday | 83°F | Sunny | 5 to 12 mph SW | 9% |
| Monday Night | 69°F | Partly Cloudy | 6 to 10 mph W | 11% |
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 Aug 4, 2026.