Union, NH Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Union, a community in Strafford County, New Hampshire.
Tonight
45°F
Mostly Clear
Mostly clear, with a low around 45. North wind 0 to 5 mph.
7-day forecast for Union
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 45°F | Mostly Clear | 0 to 5 mph N | 0% |
| Saturday | 65°F | Sunny | 0 to 5 mph N | 0% |
| Saturday Night | 46°F | Partly Cloudy | 0 mph | 0% |
| Sunday | 59°F | Rain Showers | 0 to 5 mph S | 75% |
| Sunday Night | 50°F | Rain Showers Likely | 0 to 5 mph NE | 73% |
| Monday | 65°F | Mostly Sunny | 5 to 10 mph N | 5% |
| Monday Night | 46°F | Partly Cloudy | 0 to 5 mph NE | 1% |
| Tuesday | 60°F | Partly Sunny | 5 to 10 mph NE | 1% |
| Tuesday Night | 44°F | Mostly Cloudy | 0 to 10 mph NE | 1% |
| Wednesday | 60°F | Mostly Sunny | 10 mph NE | 1% |
| Wednesday Night | 44°F | Partly Cloudy | 0 to 5 mph NE | 7% |
| Thursday | 60°F | Chance Rain Showers | 5 to 10 mph NE | 25% |
| Thursday Night | 47°F | Chance Rain Showers | 0 to 10 mph NE | 25% |
| Friday | 63°F | Chance Rain Showers | 10 mph N | 29% |
Forecast source: National Weather Service (api.weather.gov) for Union (43.491, -71.023). Updated through the day.
Growing snapshot for Union
Last spring frost
May 16
First fall frost
Sep 30
Growing season
136 days
Hardiness zone
5b
More local growing data for Union: nearby ZIP 03852 weather · frost dates · planting calendar · New Hampshire frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Sanford 2 Nnw, Me (10.6 mi from Union). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.