Derby, CT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Derby, a city in New Haven County, Connecticut.
This Afternoon
70°F
Partly Sunny
Partly sunny. High near 70, with temperatures falling to around 63 in the afternoon. Southwest wind 2 to 9 mph.
7-day forecast for Derby
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 70°F | Partly Sunny | 2 to 9 mph SW | 0% |
| Tonight | 49°F | Partly Cloudy | 2 mph S | 0% |
| Wednesday | 72°F | Mostly Sunny | 2 to 9 mph SW | 0% |
| Wednesday Night | 54°F | Mostly Cloudy | 5 mph SW | 0% |
| Thursday | 71°F | Chance Rain Showers | 2 to 10 mph S | 27% |
| Thursday Night | 59°F | Showers And Thunderstorms Likely | 2 to 6 mph SW | 59% |
| Friday | 69°F | Showers And Thunderstorms | 2 to 7 mph S | 77% |
| Friday Night | 53°F | Showers And Thunderstorms then Light Rain Likely | 3 mph W | 77% |
| Saturday | 66°F | Light Rain Likely | 5 to 8 mph N | 61% |
| Saturday Night | 43°F | Chance Light Rain | 6 mph NW | 33% |
| Sunday | 62°F | Mostly Sunny | 5 to 8 mph NW | 14% |
| Sunday Night | 42°F | Partly Cloudy then Slight Chance Light Rain | 2 to 6 mph NW | 18% |
| Monday | 59°F | Chance Light Rain | 6 to 12 mph NW | 31% |
| Monday Night | 39°F | Chance Light Rain | 7 to 13 mph NW | 31% |
Forecast source: National Weather Service (api.weather.gov) for Derby (41.326, -73.083). Updated through the day.
Growing snapshot for Derby
Last spring frost
Apr 25
First fall frost
Oct 17
Growing season
175 days
Hardiness zone
6b
More local growing data for Derby: nearby ZIP 06418 weather · frost dates · planting calendar · Connecticut frost dates
Nearby towns & communities
Ansonia
Branford Center
Cheshire Village
East Haven
Guilford Center
Heritage Village
Madison Center
Meriden
Milford city
Naugatuck
New Haven
North Haven
Northford
Orange
Quinnipiac University
Wallingford Center
Waterbury
West Haven
Woodmont
Climate data from the nearest NOAA station, Ansonia 1 Ne, Ct (1.7 mi from Derby). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.