Harman US

Thomaston, CT Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Thomaston, a community in Litchfield County, Connecticut.

Tonight
49°F
Partly Cloudy
Partly cloudy, with a low around 49. North wind around 5 mph.

7-day forecast for Thomaston

WhenTempForecastWindPrecip
Tonight 49°F Partly Cloudy 5 mph N 0%
Saturday 66°F Mostly Sunny 1 to 5 mph NE 0%
Saturday Night 50°F Mostly Cloudy 1 mph SE 1%
Sunday 63°F Rain Showers 0 to 6 mph SE 93%
Sunday Night 53°F Rain Showers 2 to 9 mph NE 93%
Monday 63°F Chance Rain Showers 6 to 10 mph NE 30%
Monday Night 48°F Slight Chance Rain Showers then Mostly Cloudy 3 to 10 mph NE 22%
Tuesday 59°F Slight Chance Rain Showers 8 to 12 mph NE 22%
Tuesday Night 46°F Mostly Cloudy 8 to 14 mph NE 8%
Wednesday 60°F Partly Sunny then Slight Chance Rain Showers 10 to 15 mph NE 15%
Wednesday Night 46°F Slight Chance Rain Showers 10 to 15 mph NE 24%
Thursday 59°F Chance Rain Showers 10 to 15 mph NE 30%
Thursday Night 47°F Chance Rain Showers 9 to 14 mph NE 34%
Friday 63°F Chance Rain Showers 9 to 14 mph N 33%

Forecast source: National Weather Service (api.weather.gov) for Thomaston (41.677, -73.083). Updated through the day.

Growing snapshot for Thomaston

Last spring frost
Apr 25
First fall frost
Oct 18
Growing season
172 days
Hardiness zone
6a

More local growing data for Thomaston: nearby ZIP 06787 weather · frost dates · planting calendar · Connecticut frost dates

Nearby towns & communities

All Connecticut locations ›

Climate data from the nearest NOAA station, Burlington, Ct (11.6 mi from Thomaston). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.