Mount Union, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Mount Union, a community in Henry County, Iowa.
Tonight
66°F
Showers And Thunderstorms Likely
A slight chance of rain showers before 11pm, then showers and thunderstorms likely between 11pm and 1am, then showers and thunderstorms. Mostly cloudy. Low around 66, with temperatures rising to around 69 overnight. Northwest wind around 5 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast for Mount Union
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 66°F | Showers And Thunderstorms Likely | 5 mph NW | 76% |
| Sunday | 71°F | Showers And Thunderstorms Likely | 5 to 15 mph N | 71% |
| Sunday Night | 57°F | Showers And Thunderstorms Likely | 10 to 15 mph NE | 64% |
| Monday | 63°F | Rain Showers | 15 mph NE | 80% |
| Monday Night | 53°F | Rain Showers Likely | 10 mph NE | 67% |
| Tuesday | 62°F | Chance Rain Showers | 10 mph NE | 35% |
| Tuesday Night | 49°F | Partly Cloudy | 5 to 10 mph NE | 4% |
| Wednesday | 65°F | Partly Sunny | 5 mph NE | 1% |
| Wednesday Night | 52°F | Partly Cloudy | 0 to 5 mph NE | 1% |
| Thursday | 68°F | Partly Sunny | 0 to 5 mph NE | 5% |
| Thursday Night | 56°F | Slight Chance Rain Showers | 0 to 5 mph NE | 17% |
| Friday | 72°F | Slight Chance Rain Showers | 0 to 5 mph NE | 17% |
| Friday Night | 57°F | Partly Cloudy | 5 mph E | 8% |
| Saturday | 73°F | Mostly Sunny | 5 mph E | 8% |
Forecast source: National Weather Service (api.weather.gov) for Mount Union (41.058, -91.391). Updated through the day.
Growing snapshot for Mount Union
Last spring frost
Apr 30
First fall frost
Oct 10
Growing season
163 days
Hardiness zone
5b
More local growing data for Mount Union: nearby ZIP 52644 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Mt Pleasant 1 Ssw, Ia (10 mi from Mount Union). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.