St. Louis is starting Friday, August 7, with clear skies and temperatures around 70 degrees, but the calm opening is a brief pause before a hotter stretch. A stray shower or thunderstorm is possible before 7 a.m. Friday, then skies should turn mostly sunny with a high near 90.
Friday Storm Chance Stays Limited
The morning rain chance is about 20%, with better odds south of Interstate 70 rather than across the city. The National Weather Service in St. Louis says storms could bring a brief heavy downpour or localized strong wind gust, although the overall severe-weather threat looks low; no watches or warnings are in effect for Missouri or Illinois.
Weekend Heat Builds Quickly
Saturday looks sunny and dry with a high near 90, though the heat index could reach 100. Sunday climbs to about 94 under mostly sunny skies, followed by a sunny Monday near 95 and another hot Tuesday around 94.
Overnight relief will be limited, with lows around 73 Friday and Saturday nights and near 77 Sunday and Monday nights. The forecast office says heat-related headlines may be needed from Sunday through Tuesday as humidity returns, making the morning the easier window for outdoor work, errands and exercise.
Storms Return Midweek
The pattern turns more unsettled Tuesday night, when the chance of showers and thunderstorms rises to about 40%. Storm chances continue Wednesday and Thursday at roughly 40% to 50%, with highs easing to 89 Wednesday and 84 Thursday.
For Friday and the weekend, keep water handy, take breaks from the afternoon sun and bring a backup plan for outdoor activities. Any storm that forms Friday could be locally wet, but the bigger story for most of St. Louis is the heat arriving after the morning's small rain risk fades.
