Key West
Florida, USA
Long-term weather forecast
Long-term weather forecast

May weather forecast and Climate
Key West, FL

A beach pier in Key West, Florida, with palm trees in the background
A beach pier in Key West, Florida, with palm trees in the background
Sunny May is basked in the brilliant daily sunshine of 11 hours with light rain up to 7 days in the month. Average lows and highs are steady between 75°F (23.9°C) to 85°F (29.4°C), as the days are noticeably warm.
Early morning is the perfect time for a bike or moped ride for people with a zeal to explore Key West in its natural surroundings. Avoid the mid-day sun and take precautions to counter the ultraviolet index of the sun at a dangerous 11. Take advantage of the low crowds on the beach and lower hotel rates during May.
  • The average high temperature in May: 85°F

The warmest month (with the highest average high temperature) is August (89.4°F).
The month with the lowest average high temperature is January (74.3°F).

  • The average low temperature in May: 75.7°F

The month with the highest average low temperature is July (79.8°F).
The coldest month (with the lowest average low temperature) is January (64.2°F).

  • The average humidity in May: 71.8%

The month with the highest relative humidity is December (76.2%).
The month with the lowest relative humidity is April (70.1%).

  • The average rainfall in May: 4.2"

The wettest month (with the highest rainfall) is September (6.5").
The driest month (with the lowest rainfall) is March (1.6").

  • The average rainfall days in May: 7.2 days

The month with the highest number of rainy days is September (16.2 days).
The month with the lowest number of rainy days is April (4.5 days).

  • The average sea temperature in May: 80.7°F

The best month for swimming (with the highest average sea temperature) is August (86.9°F).
Coldest months (with the lowest average sea temperature) are January and February (71.2°F).

  • The average daylight in May: 13h

The month with the longest days is June (Average daylight: 14h).
Months with shortest days are January, February, November and December (Average daylight: 11h).

  • The average sunshine in May: 11h

The month with most sunshine is May (Average sunshine: 11h).
The month with least sunshine is December (Average sunshine: 7.6h).

  • The average UV index in May: 11

Months with the highest UV index are April, May, June, July and August (UV index 11).
Months with the lowest UV index are January and December (UV index 6).