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 across most of South Florida this afternoon, July 12, 2025.
Rainfall chances today are likely, with Miami at 69%, Fort Lauderdale at 73%, West Palm Beach at 63%, and Naples at 64%, 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.