Miami Sizzles: Heat Advisory Hits Before Wild PM Storms Roll In

Miami is starting Friday, August 21, with clear skies and a warm, humid morning, but the easy part of the day will not last. A Heat Advisory runs from 11 a.m. to 6 p.m. across Miami-Dade and Broward, with heat-index values expected to reach 107 degrees as the city climbs near 90.

Heat Peaks Before Afternoon Storms

South winds of 6 to 10 mph will accompany mostly sunny skies through late morning, with temperatures rising through the 80s. Showers and thunderstorms become possible after 11 a.m., with the best chance during the afternoon and an overall precipitation chance near 30%, according to the National Weather Service Miami.

A few storms could bring heavy downpours, localized flooding in areas with poor drainage and sudden wind gusts. Forecasters say an isolated stronger storm could produce near-severe winds, so outdoor plans may need a flexible exit strategy.

Friday Night Stays Muggy

Storm chances linger before 8 p.m., followed by partly cloudy skies overnight. The low will fall only to around 83 degrees, and the overnight heat index could still reach 103, offering limited relief after the afternoon heat.

Weekend Forecast Keeps The Heat On

Saturday looks much the same, with mostly sunny skies, a high near 90 and a 30% chance of showers and thunderstorms after 10 a.m. Saturday night brings a 40% chance of storms before partial clearing, with a low around 82.

Sunday will be slightly cooler at 89 degrees, but storm chances rise to 40% after 2 p.m. Highs should remain near 89 to 90 through Thursday, with daily chances for showers and thunderstorms continuing even as the wettest weather gradually shifts toward inland and southwest South Florida.

Heat Advisory Safety

The National Weather Service recommends drinking plenty of fluids, staying in air conditioning, avoiding direct sun and checking on relatives and neighbors during the advisory. Outdoor workers should take frequent breaks in shaded or air-conditioned areas, and anyone showing signs of heat stroke should be moved to a cool location while 911 is called.