St. Charles, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Charles, a city in Madison County, Iowa.
Tonight
47°F
Rain Showers Likely
Rain showers likely before 2am. Cloudy, with a low around 47. West northwest wind 8 to 15 mph, with gusts as high as 21 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for St. Charles
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 47°F | Rain Showers Likely | 8 to 15 mph WNW | 64% |
| Wednesday | 52°F | Mostly Cloudy | 16 mph W | 13% |
| Wednesday Night | 43°F | Mostly Cloudy | 14 mph W | 12% |
| Thursday | 52°F | Chance Rain Showers | 12 mph WNW | 49% |
| Thursday Night | 41°F | Mostly Cloudy | 10 mph NNW | 12% |
| Friday | 52°F | Partly Sunny | 5 to 8 mph N | 5% |
| Friday Night | 35°F | Partly Cloudy | 3 mph NNW | 0% |
| Saturday | 56°F | Mostly Sunny | 1 to 5 mph WSW | 1% |
| Saturday Night | 38°F | Mostly Clear | 6 mph W | 3% |
| Sunday | 62°F | Sunny | 7 mph W | 5% |
| Sunday Night | 41°F | Mostly Clear | 8 mph SW | 1% |
| Monday | 65°F | Sunny | 8 to 12 mph SW | 0% |
| Monday Night | 43°F | Mostly Clear | 7 mph WNW | 0% |
| Tuesday | 64°F | Sunny | 6 mph NNW | 0% |
Forecast source: National Weather Service (api.weather.gov) for St. Charles (41.287, -93.807). Updated through the day.
Growing snapshot for St. Charles
Last spring frost
Apr 24
First fall frost
Oct 12
Growing season
168 days
Hardiness zone
5b
More local growing data for St. Charles: nearby ZIP 50240 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Indianola 2W, Ia (8.9 mi from St. Charles). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.