Cos Cob, CT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Cos Cob, a community in Fairfield County, Connecticut.
Today
84°F
Mostly Sunny
Mostly sunny, with a high near 84. East wind around 5 mph.
7-day forecast for Cos Cob
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Mostly Sunny | 5 mph E | 0% |
| Tonight | 64°F | Mostly Cloudy | 3 mph SW | 2% |
| Wednesday | 84°F | Partly Sunny then Slight Chance Showers And Thunderstorms | 2 to 6 mph E | 23% |
| Wednesday Night | 71°F | Chance Rain Showers | 2 to 6 mph S | 27% |
| Thursday | 89°F | Chance Showers And Thunderstorms | 2 to 8 mph SW | 41% |
| Thursday Night | 73°F | Chance Showers And Thunderstorms then Partly Cloudy | 3 to 7 mph SW | 40% |
| Friday | 91°F | Mostly Sunny then Chance Showers And Thunderstorms | 3 to 7 mph SW | 40% |
| Friday Night | 72°F | Chance Showers And Thunderstorms | 6 mph SW | 39% |
| Saturday | 88°F | Partly Sunny then Chance Showers And Thunderstorms | 3 to 8 mph SW | 31% |
| Saturday Night | 71°F | Chance Showers And Thunderstorms | 6 mph W | 31% |
| Sunday | 89°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 3 to 7 mph W | 15% |
| Sunday Night | 72°F | Slight Chance Showers And Thunderstorms then Mostly Clear | 6 mph SW | 15% |
| Monday | 91°F | Sunny | 3 to 9 mph W | 13% |
| Monday Night | 70°F | Slight Chance Rain Showers | 5 to 8 mph W | 18% |
Forecast source: National Weather Service (api.weather.gov) for Cos Cob (41.049, -73.592). Updated through the day.
Growing snapshot for Cos Cob
Last spring frost
Apr 17
First fall frost
Oct 23
Growing season
188 days
Hardiness zone
7a
More local growing data for Cos Cob: nearby ZIP 06807 weather · frost dates · planting calendar · Connecticut frost dates
Nearby towns & communities
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Candlewood Isle
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Candlewood Lake Club
Candlewood Orchards
Candlewood Shores
Cannondale
Chimney Point
Coleytown
Compo
Danbury
Daniels Farm
Darien Downtown
Dodgingtown
East Village
Fairfield University
Georgetown
Greens Farms
Greenwich
Hawleyville
Indian Field
Inglenook
Kellogg Point
Climate data from the nearest NOAA station, Stamford 5 N, Ct (5.2 mi from Cos Cob). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.