St. Charles, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Charles, a city in Madison County, Iowa.
Overnight
71°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Mostly cloudy, with a low around 71. South wind around 9 mph. Chance of precipitation is 40%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for St. Charles
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 71°F | Chance Showers And Thunderstorms | 9 mph S | 35% |
| Saturday | 82°F | Chance Showers And Thunderstorms | 9 mph WSW | 40% |
| Saturday Night | 63°F | Chance Showers And Thunderstorms | 8 mph NNW | 52% |
| Sunday | 67°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 8 to 12 mph NNE | 61% |
| Sunday Night | 57°F | Showers And Thunderstorms Likely | 12 mph NE | 61% |
| Monday | 61°F | Rain Showers Likely | 12 mph NE | 65% |
| Monday Night | 53°F | Chance Rain Showers | 9 mph NE | 54% |
| Tuesday | 60°F | Mostly Cloudy | 8 mph NE | 13% |
| Tuesday Night | 49°F | Partly Cloudy | 2 to 7 mph NE | 4% |
| Wednesday | 64°F | Mostly Sunny | 5 mph ENE | 2% |
| Wednesday Night | 52°F | Partly Cloudy | 3 mph ESE | 4% |
| Thursday | 66°F | Slight Chance Rain Showers | 3 mph ESE | 17% |
| Thursday Night | 56°F | Mostly Cloudy then Slight Chance Rain Showers | 3 mph SE | 15% |
| Friday | 67°F | Slight Chance Rain Showers | 2 to 6 mph ESE | 15% |
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 Sep 19, 2026.