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
75°F
Sunny
Sunny, with a high near 75. North wind around 7 mph.
7-day forecast for Northwest Harwinton
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 75°F | Sunny | 7 mph N | 0% |
| Tonight | 48°F | Partly Cloudy | 6 mph N | 0% |
| Saturday | 65°F | Mostly Sunny | 5 mph E | 0% |
| Saturday Night | 49°F | Mostly Cloudy | 2 mph SE | 1% |
| Sunday | 61°F | Rain Showers | 0 to 6 mph SE | 94% |
| Sunday Night | 52°F | Rain Showers | 2 to 8 mph NE | 94% |
| Monday | 62°F | Chance Rain Showers | 6 to 9 mph NE | 27% |
| Monday Night | 47°F | Slight Chance Rain Showers then Partly Cloudy | 3 to 9 mph NE | 21% |
| Tuesday | 58°F | Slight Chance Rain Showers | 10 mph NE | 21% |
| Tuesday Night | 45°F | Mostly Cloudy | 7 to 12 mph NE | 8% |
| Wednesday | 59°F | Partly Sunny then Slight Chance Rain Showers | 13 mph NE | 15% |
| Wednesday Night | 45°F | Slight Chance Rain Showers | 9 to 14 mph NE | 24% |
| Thursday | 57°F | Chance Rain Showers | 10 to 14 mph NE | 30% |
| Thursday Night | 47°F | Chance Rain Showers | 8 to 12 mph NE | 34% |
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 Sep 19, 2026.