Iron Mountain Lake, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Iron Mountain Lake, a city in St. Francois County, Missouri.
Today
86°F
Sunny
Sunny, with a high near 86. Southeast wind around 5 mph.
7-day forecast for Iron Mountain Lake
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 86°F | Sunny | 5 mph SE | 0% |
| Tonight | 66°F | Mostly Clear | 1 to 5 mph S | 0% |
| Wednesday | 90°F | Sunny | 5 mph S | 2% |
| Wednesday Night | 70°F | Partly Cloudy then Chance Showers And Thunderstorms | 5 mph S | 38% |
| Thursday | 87°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 mph S | 61% |
| Thursday Night | 69°F | Chance Showers And Thunderstorms | 3 mph S | 53% |
| Friday | 86°F | Chance Showers And Thunderstorms | 3 mph SW | 53% |
| Friday Night | 69°F | Chance Showers And Thunderstorms | 2 mph SW | 47% |
| Saturday | 88°F | Chance Showers And Thunderstorms | 3 mph SW | 28% |
| Saturday Night | 70°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 3 mph S | 17% |
| Sunday | 89°F | Sunny | 3 to 7 mph SW | 3% |
| Sunday Night | 71°F | Mostly Clear | 6 mph S | 2% |
| Monday | 91°F | Sunny | 7 mph SW | 2% |
| Monday Night | 73°F | Mostly Clear | 6 mph S | 5% |
Forecast source: National Weather Service (api.weather.gov) for Iron Mountain Lake (37.691, -90.622). Updated through the day.
Growing snapshot for Iron Mountain Lake
Last spring frost
Apr 13
First fall frost
Oct 21
Growing season
191 days
Hardiness zone
6b
More local growing data for Iron Mountain Lake: nearby ZIP 63624 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Bismarck
Bonne Terre
Desloge
Doe Run
Farmington
Frankclay
Goose Creek Lake
Knob Lick
Lake Timberline
Leadington
Leadwood
Park Hills
Terre du Lac
Wortham
Climate data from the nearest NOAA station, Farmington, Mo (12.5 mi from Iron Mountain Lake). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.