December weather forecastKey West, FL
December
Weather in December
December in Key West, Florida, characteristically enjoys warm, sunny, and dry weather. Although it is winter, the climate remains comfortable, with the sea temperature favorable for water activities. Evenings can occasionally see cooler temperatures, and it is the ideal month for those looking to escape harsh winter conditions elsewhere. This period also delights with the festive season ushering in, and the city vibrates with excitement. December's atmospheric pressure peaks to its yearly maximum, reaching 30.06" (764mm), creating clear, dry weather ideal for end-of-year celebrations.Temperature
Key West sees the arrival of December with an average high-temperature of a still warm 75.2°F (24°C), indicating a subtle variation from November. Key West's December nights exhibit a subtle drop in temperature, averaging at an agreeable 72.5°F (22.5°C), closely aligned with the daytime highs.Humidity
The average relative humidity in December is 77%.Rainfall
In Key West, Florida, in December, during 13.4 rainfall days, 1.22" (31mm) of precipitation is typically accumulated. Throughout the year, there are 199.2 rainfall days, and 31.61" (803mm) of precipitation is accumulated.Ocean temperature
In December, the average ocean temperature is 74.5°F (23.6°C).Note: Taking into account a person's sensitivity to the cold, given sunshine, wind, and air temperature, swimming in 74.5°F (23.6°C) might be pleasant. (FYI: The water temperature set for the Olympic swimming event is between 77°F (25°C) and 82.4°F (28°C).)
Daylight
The month with the shortest days is December, with an average of 10h and 36min of daylight.On the first day of December, sunrise is at 6:54 am and sunset at 5:38 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 5:49 pm EST.
Sunshine
With an average of 6.3h of sunshine, December has the least sunshine of the year.UV index
The average daily maximum UV index in December in Key West, Florida, is 6. A UV Index estimate of 6 to 7 represents a high health risk from unprotected exposure to Sun's UV rays for average individuals.Note: In December, the average maximum UV index of 6 translates into the following recommendations:
Persist with safeguards and heed sun safety doctrines. Keeping sunburn at bay is of prime importance. The time between 10 a.m. and 4 p.m. is when UV radiation is at its peak. Limit exposure to direct sunlight during these hours. Stay sun-safe with clothing that is both closely woven and worn loosely. Take note! The UV strength of the Sun elevates when reflected off water and sand.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Key West, FL
- Average high temperature in December: 75.2°F
The warmest month (with the highest average high temperature) is August (85.3°F).
The month with the lowest average high temperature is January (72.7°F).
- Average low temperature in December: 72.5°F
The month with the highest average low temperature is August (82.9°F).
The coldest month (with the lowest average low temperature) is January (68.5°F).
Average pressure in December
Key West, FL
- Average pressure in December: 30.06"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are September and October (29.93"Hg).
Average wind speed in December
Key West, FL
- Average wind speed in December: 13.8mph
The windiest months (with the highest average wind speed) are January and November (14.4mph).
The calmest month (with the lowest average wind speed) is July (9.5mph).
Average humidity in December
Key West, FL
- Average humidity in December: 77%
The month with the highest relative humidity is February (78%).
The months with the lowest relative humidity are July, August and September (74%).
Average rainfall in December
Key West, FL
- Average rainfall in December: 1.22"
The wettest month (with the highest rainfall) is September (5.12").
The driest month (with the least rainfall) is March (0.67").
Average rainfall days in December
Key West, FL
- Average rainfall days in December: 13.4 days
The months with the highest number of rainy days are August and September (23.1 days).
The month with the least rainy days is February (11 days).
Average sea temperature in December
Key West, FL
- Average sea temperature in December: 74.5°F
The best month for swimming (with the highest average sea temperature) is August (86.9°F).
The coldest months (with the lowest average sea temperature) are January and February (71.2°F).
Average daylight in December /
Average sunshine in December
Key West, FL
- Average daylight in December: 10h and 36min
The month with the longest days is June (Average daylight: 13h and 36min).
The month with the shortest days is December (Average daylight: 10h and 36min).
- Average sunshine in December: 6h and 18min
The month with the most sunshine is July (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 18min).
Average sunshine days in December
Key West, FL
- Average sunshine days in December: 12.2 days
The month with the most sunshine days is March (17 days).
The month with the least sunshine days is September (4.5 days).
Average UV index in December
Key West, FL
- Average UV index in December: 6
The months with the highest UV index are April, May, June, July, August, September and October (UV index 7).
The month with the lowest UV index is January (UV index 5).
Average cloud cover in December
Key West, FL
- Average cloud cover in December: 33
The month with the most cloud cover is January (Cloud cover 34).
The month with the least cloud cover is April (Cloud cover 23).
Average visibility in December
Key West, FL
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
