Cos Cob, CT Weather & Growing Conditions
Today
83°F
Mostly Sunny
Mostly sunny, with a high near 83. East wind around 5 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 83°F | Mostly Sunny | 5 mph E | 0% |
| Tonight | 64°F | Mostly Cloudy | 3 mph N | 2% |
| Wednesday | 83°F | Partly Sunny then Slight Chance Showers And Thunderstorms | 2 to 6 mph SE | 23% |
| Wednesday Night | 70°F | Chance Rain Showers | 5 mph S | 27% |
| Thursday | 88°F | Chance Showers And Thunderstorms | 2 to 8 mph SW | 42% |
| Thursday Night | 72°F | Chance Showers And Thunderstorms then Partly Cloudy | 3 to 7 mph SW | 40% |
| Friday | 90°F | Mostly Sunny then Chance Showers And Thunderstorms | 3 to 7 mph SW | 40% |
| Friday Night | 71°F | Chance Showers And Thunderstorms | 6 mph W | 39% |
| Saturday | 87°F | Partly Sunny then Chance Showers And Thunderstorms | 3 to 8 mph SW | 32% |
| Saturday Night | 70°F | Chance Showers And Thunderstorms | 6 mph W | 32% |
| Sunday | 88°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 3 to 7 mph W | 15% |
| Sunday Night | 71°F | Slight Chance Showers And Thunderstorms then Mostly Clear | 6 mph W | 15% |
| Monday | 90°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). Updated through the day.
Growing snapshot for Cos Cob, CT
Last spring frost
Apr 17
First fall frost
Oct 23
Growing season
188 days
Hardiness zone
7a
Explore more for Cos Cob, CT: full frost dates · planting calendar · Connecticut frost dates
Climate data from the nearest NOAA station, Stamford 5 N, Ct (5.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.