MIAMI, FL — The National Weather Service in Miami has issued a forecast of heat index values that will reach the low to mid 100s and scattered showers and thunderstorms that will focus mostly over Southwest Florida, but Southeast Florida will still see its fair share of showers and thunderstorms as well during Thursday afternoon, July 10, 2025. National Weather Service Miami South Florida Heat Indices Thursday July 10, 2025 Rainfall chances today are likely, with Miami at 59%, Fort Lauderdale at 59%, West Palm Beach at 51%, and Naples at 52%, according to the NWS. National Weather Service Miami South Florida Doppler Radar Heat Exhaustion versus Heat Stroke Take action when you see symptoms of heat exhaustion and heat stroke. To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air-conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency! Call 9 1 1. What is the Urban Heat Island Effect? The urban heat island effect occurs when urban areas become much warmer—sometimes by as much as 20°F—than nearby rural landscapes, especially during summer. According to NASA, this happens because cities have more heat-absorbing surfaces like asphalt, concrete, and buildings, and less vegetation to provide cooling through shade and evapotranspiration. Hot temperatures and high relative humidity will push heat index values to 102-105F for SE Florida and 105-107F for SW Florida before scattered showers and thunderstorms increase later this afternoon and help cool conditions down. #flwx pic.twitter.com/Cj48CfsLgd — NWS Miami (@NWSMiami) July 10, 2025