Teachers and staff at Key Biscayne’s schools are preparing for students returning to classrooms throughout the week, and they will do so under a Heat Advisory and a mix of sun and clouds.

According to the National Weather Service in Miami, the combination of a high approaching 90 degrees and high humidity is expected to drive heat index values as high as 109 across the island and much of South Florida. A stray shower or thunderstorm is possible, with ESE winds at 10 to 15 mph.

Tonight, some clouds with a stray shower or thunderstorm possible and a low of 83 degrees.

Tuesday, partly cloudy with a stray shower or thunderstorm possible. The high will be near 89 degrees, with ESE winds at 10 to 15 mph.

For hour-by-hour Key Biscayne weather updates and local radar, click here.