St. Louis, Mo. – Residents across eastern Missouri and southwest Illinois face oppressive heat and dangerous humidity through Monday evening, with a heat index climbing as high as 108 degrees. The National Weather Service has issued a Heat Advisory for much of the region, including St. Louis, Columbia, Farmington, and Edwardsville, in effect until 8 p.m. Monday.
According to the National Weather Service in St. Louis, the combination of high heat and moisture will push heat index values well into the triple digits both Sunday and Monday. The agency warns that prolonged outdoor exposure could lead to heat exhaustion or heat stroke, particularly for young children, the elderly, and those working outdoors.
A chance of thunderstorms may bring brief relief but could also deliver gusty winds and lightning late Sunday afternoon and again Monday evening. Additional storms are possible through midweek, especially Tuesday night into Wednesday.
Local emergency officials urge residents to stay in air conditioning when possible, drink plenty of water, and check on vulnerable neighbors. Cooling centers are open across the St. Louis metro area, with information available through the United Way at 2-1-1 or Cool Down St. Louis at 314-241-7668.
Heat advisories remain in place until Monday night, and forecasters caution additional alerts could be issued if extreme humidity lingers into Tuesday.
Five Day Forecast for St. Louis, MO
- Sunday: High near 99, heat index up to 107. Scattered thunderstorms late. Low around 77.
- Monday: High near 98, heat index near 109. Isolated thunderstorms possible. Low near 77.
- Tuesday: High near 96, chance of thunderstorms late. Low near 73.
- Wednesday: High near 88, showers possible in the afternoon. Low near 69.
- Thursday: Mostly sunny, cooler with a high near 86.
