St. Charles, IA Weather & Growing Conditions
Tonight
46°F
Cloudy then Slight Chance Rain Showers
A slight chance of rain showers between midnight and 2am. Cloudy. Low around 46, with temperatures rising to around 48 overnight. West northwest wind around 15 mph, with gusts as high as 21 mph. Chance of precipitation is 20%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 46°F | Cloudy then Slight Chance Rain Showers | 15 mph WNW | 19% |
| Wednesday | 53°F | Mostly Cloudy | 16 mph W | 13% |
| Wednesday Night | 43°F | Mostly Cloudy | 13 mph W | 12% |
| Thursday | 52°F | Chance Rain Showers | 12 mph WNW | 50% |
| Thursday Night | 41°F | Mostly Cloudy | 9 mph NNW | 12% |
| Friday | 52°F | Partly Sunny | 5 to 8 mph N | 5% |
| Friday Night | 35°F | Mostly Cloudy | 3 mph NNW | 0% |
| Saturday | 57°F | Mostly Sunny | 1 to 5 mph WSW | 1% |
| Saturday Night | 38°F | Mostly Clear | 6 mph W | 3% |
| Sunday | 63°F | Sunny | 7 mph W | 5% |
| Sunday Night | 41°F | Mostly Clear | 7 mph SW | 1% |
| Monday | 66°F | Sunny | 7 to 12 mph SW | 0% |
| Monday Night | 43°F | Mostly Clear | 7 mph W | 0% |
| Tuesday | 64°F | Sunny | 6 mph NNW | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for St. Charles, IA
Last spring frost
Apr 24
First fall frost
Oct 12
Growing season
168 days
Hardiness zone
5b
Explore more for St. Charles, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Indianola 2W, Ia (8.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.