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Irondale, MO Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Irondale, a city in Washington County, Missouri.

Today
98°F
Mostly Sunny
Mostly sunny, with a high near 98. Heat index values as high as 100. Southwest wind around 7 mph.

7-day forecast for Irondale

WhenTempForecastWindPrecip
Today 98°F Mostly Sunny 7 mph SW 1%
Tonight 71°F Mostly Clear 5 mph SW 3%
Sunday 95°F Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms 5 mph W 20%
Sunday Night 66°F Slight Chance Showers And Thunderstorms then Showers And Thunderstorms Likely 1 to 5 mph N 58%
Monday 82°F Showers And Thunderstorms Likely 2 to 6 mph N 69%
Monday Night 58°F Showers And Thunderstorms Likely 3 to 7 mph N 69%
Tuesday 72°F Slight Chance Showers And Thunderstorms then Partly Sunny 3 to 8 mph N 24%
Tuesday Night 52°F Partly Cloudy 2 to 8 mph N 10%
Wednesday 74°F Mostly Sunny 2 to 7 mph N 2%
Wednesday Night 52°F Partly Cloudy 0 to 6 mph N 1%
Thursday 76°F Mostly Sunny 0 to 6 mph N 3%
Thursday Night 54°F Partly Cloudy 0 to 6 mph N 4%
Friday 77°F Mostly Sunny 0 to 6 mph NE 10%
Friday Night 54°F Partly Cloudy 0 to 6 mph NE 8%

Forecast source: National Weather Service (api.weather.gov) for Irondale (37.837, -90.670). Updated through the day.

Growing snapshot for Irondale

Last spring frost
Apr 11
First fall frost
Oct 28
Growing season
198 days
Hardiness zone
6b

More local growing data for Irondale: nearby ZIP 63648 weather · frost dates · planting calendar · Missouri frost dates

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Climate data from the nearest NOAA station, Potosi 4 Sw, Mo (9.5 mi from Irondale). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.