St. Louis is starting Saturday mostly clear, but the pleasant-looking sky is misleading: temperatures will climb to about 95 degrees, with humidity making it feel as hot as 110. The dangerous heat continues Sunday before a cold front brings a noticeable cooldown Monday.
An Extreme Heat Warning is in effect through 9 p.m. Sunday for the St. Louis area. The National Weather Service says heat-related illness risks increase significantly during extreme heat and high humidity, urging residents to drink plenty of fluids, stay in air conditioning when possible, avoid direct sun and check on neighbors.
Saturday Brings Little Relief
Saturday will be partly sunny with a southwest breeze around 3 to 7 mph, but the wind will not do much to soften the heat. The low will only fall to about 78 degrees Saturday night, and the overnight heat index could still reach 107.
Rain chances are low in St. Louis on Saturday, although storms farther north could be a different story. The National Weather Service St. Louis office is tracking a Flood Watch through 10 a.m. Saturday in parts of northeast Missouri and west-central Illinois, where slow-moving thunderstorms may produce bursts of very heavy rain.
Sunday Stays Hot Before The Front Arrives
Sunday looks much like Saturday in the city, with partly sunny skies, a high near 95 and heat index values again approaching 110. A few showers or thunderstorms may develop later Sunday, especially near the approaching front, with the chance increasing Sunday night.
Sunday night temperatures should dip to around 73 degrees, with a 30% chance of showers and thunderstorms. Any storms that form could bring brief heavy rain and gusty winds, though the overall severe-weather threat is expected to remain limited.
Monday Finally Feels More Manageable
Monday is the payoff for surviving the weekend heat. A slight chance of early showers will give way to mostly sunny skies and a high near 86, while Monday night falls to about 70.
Tuesday rebounds to around 91 degrees under sunny skies, followed by another chance of showers and thunderstorms Wednesday as temperatures reach the low 90s. The more comfortable stretch arrives Thursday and Friday, when highs should stay near 83 and overnight lows fall into the mid-60s.
