May Weather in Keys, United States

Last updated: June 24, 2025

In Keys, United States, the average temperature in May hovers around 21°C (69°F), with a range from a cool 6°C (43°F) to a warm 34°C (93°F). Expect about 212 mm (8.3 in) of precipitation spread over 13 days, contributing to an average humidity of 83%.

May Temperature in Keys

In May in Keys, the average temperature is 21°C (69°F). Maximums can reach 34°C (93°F), and minimums can dip as low as 6°C (43°F). This makes Keys a great destination for travelers looking for mild weather with a mix of warm days and cool nights.

May Weather in Keys: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Keys, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Keys, May typically has an average temperature of 21°C (69°F), with highs reaching up to 34°C (93°F) and lows dropping to around 6°C (43°F).

Data source: Temperature data for Keys generated using information from the Copernicus Climate Change Service.

May Precipitation in Keys

In Keys in May, the precipitation amount is 212 mm (8.3 in) spread over 13 days.

May Precipitation Trends in Keys

The chart displays monthly precipitation patterns in Keys, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Keys, May typically receives around 212 mm (8.3 inches) of precipitation spread over approximately 13 days.

Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

May Humidity in Keys

In Keys in May, humidity is 83%. With an average temperature of 21°C (69°F), this humidity feels like a heavy blanket enveloping you, making travel feel sticky and challenging as you navigate the damp air.

May Average Humidity in Keys

This chart illustrates the average monthly humidity levels in Keys, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Keys is approximately 83%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Keys

In Keys in May, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Keys.

Maximum UV Index Levels in Keys for May

The chart shows the monthly maximum UV Index (UVI) for Keys in May, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In May, the maximum UV index in Keys typically reaches 10, which falls under the very high exposure category.

Data source: Keys May UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How May Weather in Keys Compares to Other Months

Weather in Keys varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Keys, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Keys, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	4°C (40°F)	89 mm (3.5 inches)	79%	moderate
February Weather	6°C (42°F)	100 mm (4.0 inches)	78%	high
March Weather	12°C (54°F)	134 mm (5.3 inches)	75%	high
April Weather	15°C (59°F)	158 mm (6.2 inches)	75%	very high
May Weather	21°C (69°F)	212 mm (8.3 inches)	83%	very high
June Weather	26°C (78°F)	78 mm (3.1 inches)	81%	extreme
July Weather	28°C (82°F)	105 mm (4.1 inches)	78%	extreme
August Weather	26°C (80°F)	129 mm (5.1 inches)	68%	very high
September Weather	24°C (76°F)	78 mm (3.1 inches)	64%	very high
October Weather	17°C (62°F)	153 mm (6.0 inches)	71%	high
November Weather	10°C (50°F)	66 mm (2.6 inches)	82%	moderate
December Weather	7°C (45°F)	83 mm (3.3 inches)	87%	moderate