Herculaneum, MO Weather & Growing Conditions
Today
99°F
Mostly Sunny
Mostly sunny, with a high near 99. Heat index values as high as 102. Southwest wind around 6 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 99°F | Mostly Sunny | 6 mph SW | 1% |
| Tonight | 71°F | Partly Cloudy | 3 mph SW | 4% |
| Sunday | 94°F | Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms | 5 mph W | 23% |
| Sunday Night | 66°F | Slight Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 mph N | 58% |
| Monday | 81°F | Showers And Thunderstorms Likely | 3 to 7 mph N | 67% |
| Monday Night | 58°F | Showers And Thunderstorms Likely | 3 to 8 mph N | 67% |
| Tuesday | 72°F | Slight Chance Rain Showers then Partly Sunny | 6 to 9 mph N | 24% |
| Tuesday Night | 53°F | Mostly Cloudy | 2 to 9 mph N | 7% |
| Wednesday | 74°F | Mostly Sunny | 3 to 7 mph N | 2% |
| Wednesday Night | 53°F | Partly Cloudy | 1 to 6 mph N | 1% |
| Thursday | 77°F | Mostly Sunny | 1 to 6 mph N | 2% |
| Thursday Night | 55°F | Partly Cloudy | 1 to 5 mph NE | 4% |
| Friday | 77°F | Partly Sunny | 1 to 6 mph NE | 8% |
| Friday Night | 55°F | Partly Cloudy | 1 to 5 mph NE | 7% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Herculaneum, MO
Last spring frost
Apr 9
First fall frost
Oct 26
Growing season
197 days
Hardiness zone
7a
Explore more for Herculaneum, MO: full frost dates · planting calendar · Missouri frost dates
Climate data from the nearest NOAA station, Festus, Mo (2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.