Key West Weather
The weather in Key West offers a sub-tropical climate offers year-round sports and recreational opportunities. Winter, spring, and fall are filled with lots of sunshine.
• The hottest month is August with an average high of 89° F and an average low of 78° F. In January the average high temperature is 74° F and the average low is 65° F.
• There have never been frost or freezing conditions in Key West.
• Normal annual precipitation is 39 plus inches, with the largest monthly totals accumulating from July through September.
Subtropics marked by two distinct seasons
• Weather is what brings a lot of people to Southern Florida - particularly during the dry, mild winter.
• It's also what drives a lot of people away - particularly during the hot, rainy, sweaty, sticky summer.
• Welcome to the subtropics, an area just outside the tropics, which lie between the Tropic of Cancer and the Tropic of Capricorn.
GENERAL WEATHER SAFETY
• • When lightning flashes, count the number of seconds before thunder is heard. Divide the number by five. The answer is the approximate distance in miles from the lightning.
• • Never seek refuge from a storm under a tree
• • Make sure you are not the highest object around you
• • Avoid open fields, open water, beaches
• • If you are on the road, stay in your car
• • Avoid heavy exertion during the hottest part of the day - noon to 3 p.m.
• • Drink plenty of fluids, especially water. Remember, alcohol and caffeine increase dehydration n Wear a hat and sunscreen
• Our subtropical weather is marked by two distinct seasons - the rainy season, part of which is hurricane season, and the dry season, part of which is windsurfing season.
• During the rainy season, May 15 to Oct. 15, Southern Florida receives 42 of its annual 53 inches of rain.
• Rainy season temperatures average highs in the high 80s and low 90s and lows in the 70s.
• A typical rainy-season day in Southern Florida starts with a hot, humid morning, followed by a hotter afternoon, clouds moving in from the east, and sometimes violent thunderstorms.
• The frequency of summer thunderstorms has made Southern Florida the lightning capital of the world, so it's a good idea to seek shelter as the clouds roll in.
• Hurricane season runs from June 1 to Nov. 30
• Emergency managers suggest that residents educate themselves about hurricanes and be prepared, just in case.
• In contrast to Southern Florida's rainy season, the dry season is, well, dry.
• Eleven inches of rain spread over six months doesn't exactly put us in the same arid league with the Sahara, but the countryside can get pretty parched.
• In one of those curious hydrological coincidences, the dry season also happens to be tourist season, so we have all those extra people using up the available water that isn't replenished because it's the dry season.
• So water levels in aquifers can drop, and the South Florida Water Management District can impose water-use restrictions.
• All this dryness can lead to serious wildfires, and residents are urged to clear vegetation around their homes.
• People should never throw cigarette butts from car windows - that practice is bad for the environment at any time - but during the dry season, it can easily and quickly spark a major fire.
• Dry season temperatures average highs in the 70s and lows in the 50s.
• But things can get chilly around here.
• The big factors are cold fronts that occasionally blast through Southern Florida, bringing nasty cold rain and leaving behind cold air.
• You can usually tell when a cold front is coming without even looking at a weather map.
• Southern Florida's prevailing winter winds are light and easterly, but a couple of days before a front hits, winds pick up and clock around to the south - the winds are warm and the days sunny.
• This is when area windsurfers load up their gear and head to their favorite sailing sites.
• As the front approaches, winds shift to the Southern, then west - winds still warm, days still sunny.
• Eventually, the front appears on the horizon like a long, gray wall; when it hits, the wind jerks abruptly around to the north, and the air behind the front feels as if somebody up north left the door open on a giant freezer.
• Fortunately, cold temperatures following a front usually don't last long.
• Within a few days, skies clear, temperatures warm, and once again, Southern Florida shows off the weather that attracts all those winter visitors.
• Then, within a few weeks, the overall dry, mild dry season gives way to the rainy, sweaty rainy season that drives them all away.
The above article was written by By KEVIN LOLLAR, firstname.lastname@example.org Published by news-press.com on November 3, 2003.
His emphasis was on the southwest area of Florida just above the Everglades, however, the article primarily relates to the Keys as well.
The Keys Temperature Annual high average
• Month Air
• January 7 4
• February 75
• March 78
• April 81
• May 85
• June 87
• July 89
• August 89
• September 88
• October 84
• November 80
• December 76
Water temperatures go from 69 in January to 87 in July and August.
Other Keys Weather Indicators
• Average Wind Speed 10.9
• Clear Days 104
• Partly Cloudy Days 155
• Cloudy Days 107
• Avg. Relative Humidity 74.5. To see stats by the month, go to
*Although it looks like we have lots of cloudy days, the sun is out almost year round and the clouds are partial-not like in the Northwest where it will stay overcast and dark for weeks on end.
*Also, although we do get rain here-it is a tropical rain and comes and goes quickly, generally acts as a refresher to the hot days.
To see average January temperatures across the United States go to http://www.mapsofworld.com/usa/thematic-maps/usa-temperature-january.html
Compare where you live or want to live in Florida. For more specific info, look at the area you are interested in and go to the weather page.
So what about Hurricanes, the rainy season and humidity?
We are a tropical climate, so our rainy season comes in the summer. Generally, it will rain hard for a half hour then subside. It does get humid then. Although not as bad as you’d think. Our water breezes really help cool us off.
Despite four devastating hurricanes in 2004, the number of Florida visitors rose 7% to an all-time high of 79.8 million last year and is on target to hit 80 million this year.
To think about:
If you live on the coast you stand the greatest chance of having one affect you. Some areas of Florida have gone fifty years plus without one but you never know.
In my opinion, the best thing you can do is buy a home that was built after Andrew-August 92 that was built to stricter building codes. Have window protection and a backup generator and make sure your insurance is up to date. If they ask you to leave, do it!
Realize-If you live in an older home that was not built up to the stricter building codes (After Hurricane Andrew-August 1992) or you live in a mobile home you stand the best chance of having major structural damage.
Living on the beach in a mobile home is asking for it. Although you may never have a problem, you’re still definitely taking your chances. Barrier islands and open-water Ocean or Gulf front are the most prone to damage.
I prefer the threat of a hurricane however as opposed to an earthquake. At least you have a warning.
• For current information about hurricanes go to http://www.nhc.noaa.gov/
• For current weather forecasts by cities go to http://iwin.nws.noaa.
*Living in a waterfront home typically means that you will pay a higher Insurance premium. The insurance is higher due to flood and wind concerns.
Part of this is also because the pricing on these homes is higher so there is more value to insure against.
Having said all this, I can’t imagine living elsewhere. It is really great to wake up and it’s sunny out.
We spend over half our lives indoors…so when you do go outside, wouldn’t it be nice if it was warm