Union, NH Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Union, a community in Strafford County, New Hampshire.
Tonight
48°F
Mostly Cloudy
Mostly cloudy, with a low around 48. South wind around 0 mph.
7-day forecast for Union
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 48°F | Mostly Cloudy | 0 mph | 4% |
| Wednesday | 74°F | Mostly Sunny | 5 to 10 mph SW | 6% |
| Wednesday Night | 53°F | Partly Cloudy | 5 mph SW | 3% |
| Thursday | 70°F | Scattered Rain Showers | 5 to 10 mph SW | 38% |
| Thursday Night | 58°F | Isolated Rain Showers | 5 mph SW | 16% |
| Friday | 67°F | Light Rain Likely | 0 to 5 mph SW | 67% |
| Friday Night | 52°F | Light Rain | 0 to 5 mph NE | 82% |
| Saturday | 59°F | Light Rain Likely | 5 mph N | 73% |
| Saturday Night | 42°F | Chance Light Rain | 5 mph NW | 54% |
| Sunday | 56°F | Chance Light Rain | 5 to 10 mph W | 32% |
| Sunday Night | 37°F | Partly Cloudy | 5 mph W | 14% |
| Monday | 53°F | Slight Chance Light Rain | 5 to 15 mph W | 20% |
| Monday Night | 35°F | Slight Chance Light Rain | 5 to 10 mph W | 18% |
| Tuesday | 54°F | Slight Chance Light Rain | 10 to 15 mph W | 17% |
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 Nov 4, 2026.