Northwest Harwinton, CT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Northwest Harwinton, a community in Litchfield County, Connecticut.
This Afternoon
80°F
Sunny
Sunny, with a high near 80. West wind around 3 mph.
7-day forecast for Northwest Harwinton
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 80°F | Sunny | 3 mph W | 0% |
| Tonight | 60°F | Partly Cloudy | 2 mph SW | 1% |
| Wednesday | 80°F | Patchy Fog then Partly Sunny | 0 to 5 mph SW | 10% |
| Wednesday Night | 65°F | Slight Chance Rain Showers | 0 to 3 mph SW | 20% |
| Thursday | 84°F | Chance Showers And Thunderstorms | 0 to 7 mph SW | 67% |
| Thursday Night | 68°F | Chance Showers And Thunderstorms then Isolated Showers And Thunderstorms | 5 mph SW | 67% |
| Friday | 85°F | Mostly Sunny then Scattered Showers And Thunderstorms | 2 to 6 mph W | 52% |
| Friday Night | 66°F | Scattered Showers And Thunderstorms | 3 mph W | 52% |
| Saturday | 83°F | Partly Sunny then Chance Showers And Thunderstorms | 1 to 7 mph W | 41% |
| Saturday Night | 65°F | Chance Showers And Thunderstorms | 3 mph W | 41% |
| Sunday | 84°F | Mostly Sunny | 1 to 6 mph W | 12% |
| Sunday Night | 66°F | Mostly Clear | 3 mph SW | 12% |
| Monday | 85°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 2 to 8 mph W | 21% |
| Monday Night | 64°F | Slight Chance Showers And Thunderstorms | 3 to 7 mph W | 21% |
Forecast source: National Weather Service (api.weather.gov) for Northwest Harwinton (41.776, -73.079). Updated through the day.
Growing snapshot for Northwest Harwinton
Last spring frost
May 8
First fall frost
Oct 5
Growing season
151 days
Hardiness zone
6a
More local growing data for Northwest Harwinton: nearby ZIP 06791 weather · frost dates · planting calendar · Connecticut frost dates
Nearby towns & communities
Bantam
Bethlehem Village
Bridgewater
Canaan
Cornwall
Cornwall Bridge
Falls Village
Gaylordsville
Lakeville
Litchfield
New Hartford Center
New Milford
New Preston
Norfolk
Oakville
Pleasant Valley
Sharon
Terryville
Thomaston
Torrington
Watertown
West Cornwall
Winsted
Woodbury Center
Climate data from the nearest NOAA station, Bakersville, Ct (6.2 mi from Northwest Harwinton). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.