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.
This Afternoon
96°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Mostly sunny. High near 96, with temperatures falling to around 92 in the afternoon. Heat index values as high as 101. South wind around 2 mph. Chance of precipitation is 30%.
7-day forecast for Iron Mountain Lake
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 96°F | Chance Showers And Thunderstorms | 2 mph S | 25% |
| Tonight | 71°F | Slight Chance Showers And Thunderstorms then Mostly Clear | 3 mph S | 20% |
| Saturday | 96°F | Mostly Sunny | 6 mph SW | 3% |
| Saturday Night | 71°F | Partly Cloudy | 5 mph SW | 0% |
| Sunday | 93°F | Sunny | 5 mph W | 7% |
| Sunday Night | 67°F | Mostly Cloudy then Chance Showers And Thunderstorms | 3 mph N | 43% |
| Monday | 83°F | Showers And Thunderstorms Likely | 5 mph N | 64% |
| Monday Night | 60°F | Showers And Thunderstorms Likely | 6 mph N | 64% |
| Tuesday | 73°F | Partly Sunny | 8 mph N | 14% |
| Tuesday Night | 54°F | Partly Cloudy | 3 to 8 mph N | 8% |
| Wednesday | 73°F | Mostly Sunny | 6 mph N | 3% |
| Wednesday Night | 53°F | Partly Cloudy | 1 to 5 mph N | 1% |
| Thursday | 75°F | Mostly Sunny | 1 to 6 mph N | 3% |
| Thursday Night | 55°F | Partly Cloudy | 1 to 5 mph N | 4% |
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 Sep 19, 2026.