Frontenac, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Frontenac, a city in St. Louis County, Missouri.
This Afternoon
97°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Sunny, with a high near 97. Heat index values as high as 105. Southeast wind around 2 mph. Chance of precipitation is 30%.
7-day forecast for Frontenac
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 97°F | Chance Showers And Thunderstorms | 2 mph SE | 26% |
| Tonight | 75°F | Slight Chance Showers And Thunderstorms then Mostly Clear | 5 mph SE | 23% |
| Saturday | 98°F | Mostly Sunny | 3 to 7 mph SW | 5% |
| Saturday Night | 75°F | Partly Cloudy | 6 mph SW | 2% |
| Sunday | 93°F | Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms | 6 mph W | 21% |
| Sunday Night | 69°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 7 mph N | 62% |
| Monday | 80°F | Showers And Thunderstorms Likely | 8 mph N | 72% |
| Monday Night | 61°F | Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms | 6 to 9 mph N | 72% |
| Tuesday | 72°F | Slight Chance Rain Showers then Mostly Cloudy | 9 mph N | 22% |
| Tuesday Night | 56°F | Mostly Cloudy | 5 to 8 mph N | 6% |
| Wednesday | 74°F | Mostly Sunny | 7 mph N | 1% |
| Wednesday Night | 57°F | Partly Cloudy | 6 mph N | 1% |
| Thursday | 75°F | Mostly Sunny | 6 mph N | 3% |
| Thursday Night | 59°F | Partly Cloudy | 5 mph NE | 3% |
Forecast source: National Weather Service (api.weather.gov) for Frontenac (38.630, -90.419). Updated through the day.
Growing snapshot for Frontenac
Last spring frost
Apr 4
First fall frost
Oct 29
Growing season
206 days
Hardiness zone
7a
More local growing data for Frontenac: nearby ZIP 63131 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Affton
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Bel-Nor
Bel-Ridge
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Bellefontaine Neighbors
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Breckenridge Hills
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Bridgeton
Calverton Park
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Chesterfield
Clarkson Valley
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Cool Valley
Country Club Hills
Country Life Acres
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Creve Coeur
Crystal Lake Park
Dellwood
Des Peres
Edmundson
Climate data from the nearest NOAA station, St Charles 7 Ssw, Mo (6.5 mi from Frontenac). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.