Key West Weather Averages
Key West, Florida basks in warm and sunny weather year round. The delightful climate can get interrupted by severe storms though, particularly from August to October.
This page gives detailed information on the annual temperature, precipitation, sun, humidity, wind and storm averages for Key West. The numbers here are historical averages based on climate data gathered at the Key West International Airport, located on Key West Island.
|84 °F||annual average high||29 °C|
|74 °F||annual average low||23 °C|
Key West's coldest days of the year usually occur in mid January when the daily maximum temperature averages 76 degrees Fahrenheit (24 degrees Celsius) and the minimum averages 65 °F (18 °C).
The year's hottest days are normally from late July to early August. The average temperature peaks then with daily highs of 91 °F (33 °C) and nighttime lows of 81 °F (27 °C).
|57 days||90 °F max. or more (32 °C)|
|100 days||70 °F min. or less (21 °C)|
Key West averages 274 days a year when the thermometer reaches into the 80s °F (over 26 °C). The temperature normally doesn't climb above 100 °F (38 °C), even on the hottest days.
The thermometer dips to 60 °F (16 °C) or below on an average of 19 nights a year. Key West doesn't usually ever get as cold as 40 °F (4 °C).
|40.4 in||total precipitation||1027 mm|
|107 days||with rainfall|
September is usually the wettest month of the year in Key West, while February and March are the driest.
|104 days||clear skies|
The sun's rays reach the ground in Key West during 76 percent of daylight hours on average year round, for a total of 3371 hours annually. Typically on 104 days a year the sky is mainly clear, with at most 30 percent cloud cover.
Sunlight in Key West averages 12 hours and 9 minutes a day. The shortest days of the year in mid December have 10 hours and 37 minutes of daylight. The year's longest days in mid June last 13:40 from sunrise to sunset.
|74 %||average humidity|
The annual average for relative humidity in Key West ranges throughout the day from 82 percent at 7:00 am to 69 percent at 1:00 pm standard time.
|Local Time||1 am||4 am||7 am||10 am||1 pm||4 pm||7 pm||10 pm||Humidity %||78||79||79||71||67||67||73||76|
|10.9 mph||wind speed average||17.5 kph|
April is usually the windiest month for Key West, and the wind is calmest during August.
|11 days||precipitation of 1 inch (25 mm) or more|
|67 days||with thunderstorms a year|
|22 %||chance a named storm makes landfall|
Thunderstorms can appear over Key West during any month but are most common from June to September.
In any year, there's a 22 percent probability that a hurricane will reach land in Monroe county, which includes Key West. For major hurricanes of category 3 to 5, the likelihood drops to 8 percent. Named storms usually arrive during the months of June to November, while hurricanes are generally restricted to August, September and October.
The chances that a wind gust reaches 40 miles per hour (64 kilometres an hour) or greater is 33 percent a year. Intense hurricane force winds that top 115 mph (185 kph) have a 4 percent probability of blasting the county.
The weather data here are long-term averages provided by the US National Centers for Environmental Information (NCEI). Temperature and precipitation are 1991-2020 normals while humidity and thunderstorms are 1961-1990 normals. The named storm and wind gust probability information comes from United States Landfalling Hurricane Probability Project of Colorado State University and Bridgewater State University.