Key Biscayne Seasonal temperature break down - The average median temperature March through May is approximately 77°F with highs averaging at 79°F and lows averaging at 74°F. June through August has an approximate average median temperature of 83°F with highs averaging at 86°F, lows typically average at 80°F. Average median temperatures September through November average out at 80°F, high temperatures average out at 83°F and lows average at 77°F.
The average median temperature December through February is approximately 72°F with highs averaging at 76°F, lows average out at 69°F.
The average Key Biscayne annual median temperature averages out at approximately 78°F. The coldest month in Key Biscayne is January with a median temperature of 69°F, the average high for the month of January is 74°F with an average low of 64°F. The hottest month in Key Biscayne is July with an approximate median temperature of 84°F, the average high for the month of July is 86°F with an average low of 81°F.