Great question!
There are a several factors to consider when planning a visit to Key West: weather, crowds, hurricanes, and island-wide events.
When the weather’s best here, crowds swell. Certain months can be almost unbearably hot and humid. During rainy season, we’re prone to tropical storms and hurricanes that might cut your trip short.
If you go off-season, you may find that restaurant you’re dying to go to is closed, or if it’s high-season, it might be too crowded for you to get a reservation. Prices tend to change seasonally, too. You might get a bargain visiting during our hottest months, but will it be it worth it?
Let me break it down it for you.
Jan and February in Key West means “high-season.” Everyone’s here trying to get a little sun while the rest of the country freezes. It doesn’t rain often. Temperatures sometimes drop to the high 50’s Fahrenheit at night when a cold front passes through, but usually the weather is divine, 70’s and sunny, with water temperatures around 72-74 degrees Fahrenheit.
March and April in Key West brings college kids on spring break, honking the horns of their rental scooters and partying on all the beaches. It’s also family vacation time for people with children who can’t travel while school’s in session. At the end of April, all the locals come out to an event called the Conch Republic Days. Fish are biting. The weather is ahh-mazing.
May is one of the best months to visit Key West! Officially, it’s “off-season,” meaning less crowds, but it’s not summer-hot yet. Spring migration is underway, if you enjoy watching birds.
June and July in Key West brings the heat, with temperatures consistently in the 80’s. The “snowbirds” (people who live on the island only in the winter) have left. In June, Gay Pride gives the island a burst of tourism, and in July, many international travelers and visitors with kids on summer break endure heat and humidity to partake in our beaches and water activities. Water temperatures tend to be in the mid to high 70’s.
August, September and October in Key West is sticky and slow. These are the months you’re likely to be bothered by temperatures in the 90’s, rain, tropical storms and hurricanes. You’ll find discounted hotel prices and deals at restaurants, but some places close for a month or more this time of year. Womanfest mid-Sept gives the island a boost of estrogen. Even getting in the water offers little relief, with water temperatures up into the 80’s.
But then, at the end of October, there’s Fantasy Fest! 10 days of crazy costumed parties and parades draws thousands of revelers. Hotel prices skyrocket. Downtown is constantly packed. As Fantasy Fest has many adult-themed parties, it’s not a great time to bring children, but it’s the BEST time to come if you want to fly your freak flag and let it all hang out.
November in Key West (before Thanksgiving) is one of the nicest times to visit! Hurricane season is pretty much over, and it’s not as crowded as it will get over the holidays. The weather is usually temperate, and the birds are migrating back to the islands for the winter. You’ll probably even get to see some early Christmas decorations!
December in Key West, From Thanksgiving onward, is high season, busy, busy, busy! The week between Christmas and New Year’s gets especially crowded and crazy, and the locals, frankly, call this “Hell Week.” The weather is perfect, though, and the island’s holiday lights and festive atmosphere can’t be beat. New Year’s Eve is off the chain.
So May and early November have beautiful weather without huge crowds. If you’re looking for a party, show up in late October or New Year’s Eve. If you’re willing to put up with bad weather for the sake of the least crowds and the cheapest prices, try September and early October.
In short, the best time to visit Key West truly is ANYTIME!