Cool Valley, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Cool Valley, a city in St. Louis County, Missouri.
Today
90°F
Sunny
Sunny, with a high near 90. South wind around 5 mph.
7-day forecast for Cool Valley
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 90°F | Sunny | 5 mph S | 0% |
| Tonight | 71°F | Mostly Clear | 6 mph SE | 0% |
| Wednesday | 91°F | Sunny | 3 to 7 mph S | 12% |
| Wednesday Night | 73°F | Chance Showers And Thunderstorms | 5 to 8 mph S | 70% |
| Thursday | 87°F | Showers And Thunderstorms Likely | 6 mph S | 70% |
| Thursday Night | 72°F | Chance Showers And Thunderstorms | 5 mph SE | 29% |
| Friday | 88°F | Chance Showers And Thunderstorms | 5 mph SW | 29% |
| Friday Night | 72°F | Chance Showers And Thunderstorms | 5 mph S | 28% |
| Saturday | 90°F | Chance Showers And Thunderstorms then Mostly Sunny | 5 mph S | 28% |
| Saturday Night | 75°F | Mostly Clear | 7 mph S | 6% |
| Sunday | 93°F | Sunny | 6 to 9 mph SW | 6% |
| Sunday Night | 77°F | Mostly Clear | 8 mph S | 5% |
| Monday | 94°F | Mostly Sunny | 8 mph SW | 5% |
| Monday Night | 77°F | Slight Chance Showers And Thunderstorms | 8 mph S | 17% |
Forecast source: National Weather Service (api.weather.gov) for Cool Valley (38.725, -90.306). Updated through the day.
Growing snapshot for Cool Valley
Last spring frost
Apr 2
First fall frost
Nov 4
Growing season
215 days
Hardiness zone
7a
More local growing data for Cool Valley: nearby ZIP 63121 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Affton
Ballwin
Bel-Nor
Bel-Ridge
Bella Villa
Bellefontaine Neighbors
Bellerive Acres
Berkeley
Beverly Hills
Black Jack
Breckenridge Hills
Brentwood
Bridgeton
Calverton Park
Castle Point
Champ
Charlack
Chesterfield
Clarkson Valley
Clayton
Concord
Country Club Hills
Country Life Acres
Crestwood
Creve Coeur
Crystal Lake Park
Dellwood
Des Peres
Edmundson
Ellisville
Climate data from the nearest NOAA station, St Louis Lambert Intl Ap, Mo (5 mi from Cool Valley). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.