Keys and Monroe County Weather

The Keys 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 has 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.
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. 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 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, dry season is, well,
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 dry
season, it can easily and quickly spark a major fire.
Dry season temperatures average highs in the 70s and lows in the
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 unsubtropical,
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 wind surfers 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
Within a few days, skies clear, temperatures warm, and once again,
Southern Florida shows off the weather that attracts all those winter
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,
Published by 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

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 rou.

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
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

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 would 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 on:
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

Living on the beach in a mobile home is asking for it. Although,
you may never have a problem, you are still definitely taking your
chances. Barrier islands and open-water Ocean or Gulf front are the
most prone to damage.
For current information about hurricanes go to
For current weather forecasts by cities go to
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, it
would be nice if it was warm