St. Louis, Missouri – Humidity will surge across Missouri and Illinois heading into the weekend, with thunderstorms likely to interrupt outdoor plans Friday, particularly in southeastern Missouri and southwestern Illinois.
According to the National Weather Service in St. Louis, showers and storms could develop as early as Thursday night, with rain chances peaking Friday at 60–90% in the southern portions of both states. Despite the wet outlook, meteorologists say the region is not facing a total washout.
Daily highs will climb into the upper 70s and mid-80s through Sunday, with increasing moisture making conditions feel sticky and uncomfortable. Southeastern Missouri and southern Illinois—including cities like Cape Girardeau, Poplar Bluff, and Carbondale—will see the greatest daily rain chances.
Skies are expected to gradually clear by the weekend, though isolated storms could linger during the afternoon hours. Residents are urged to monitor for any flood advisories, especially in low-lying or poorly drained areas.
Clouds should decrease by Saturday, but the humidity will stick around into early next week. Another update is expected by Friday morning if additional storm warnings are issued.
