Worst time to visit Key West

The worst month to visit Key West is September

September is the wettest month of the year (189mm) and the statistical peak of the Atlantic hurricane season. Days sit at 30°C with 27°C nights that never cool off, and sunshine drops to 10 hours. It is also the emptiest, cheapest month — which tells you how the trade-off is generally judged.

Hurricane Irma made landfall at Cudjoe Key, 30km up the Overseas Highway, on September 10, 2017, as a Category 4. Wilma (October 2005) put much of Key West under water from storm surge; Georges (September 1998) and the 1935 Labor Day hurricane are the older benchmarks. The Keys sit at the meeting point of Gulf and Atlantic storm tracks — a system heading for either coast can hit here first.

Why August and September are genuinely difficult

• Hurricane exposure with one road out. The Overseas Highway is the only land route, so Monroe County issues mandatory visitor evacuation orders early — often 48 hours before a storm — and the road gridlocks within hours. Register for alerts with Monroe County Emergency Management and track systems at the NOAA National Hurricane Center.
• Heat and humidity. 30°C days with 28°C nights and near-total humidity; the heat index on Duval Street regularly passes 38°C by early afternoon.
• Rain. 149mm in August and 189mm in September, in violent afternoon thunderstorms that flood Old Town streets.
• Reduced services. Some restaurants and guesthouses take their annual break in September; the reef trips and Dry Tortugas ferry cancel more often for rough water.

The other "wrong" time: Fantasy Fest

The last ten days of October bring Fantasy Fest — an adult-oriented costume festival that fills every room in town and takes over Duval Street:

• Guesthouses sell out months ahead at rates well above the winter peak
• Duval Street is closed to traffic and body paint is the dress code
• Not the week for families, or for anyone wanting a quiet Key West

If Fantasy Fest is the trip, book by spring. If it isn't, avoid the last week of October entirely — early November, a few days later, is one of the best-value windows of the year.

If you have to travel in late summer, here's what to do

• Buy travel insurance with named-storm coverage before a storm is named — and confirm it covers mandatory evacuation, which standard policies often do not.
• Fly into Key West (EYW) rather than driving from Miami in August–September; if an evacuation is ordered, you leave on a plane instead of sitting in a four-hour queue on US-1.
• Do the water early. Reef snorkel trips and the Dry Tortugas day trip are calmer and clearer in the morning; storms build after 2pm.
• Plan indoor afternoons: the Hemingway Home, the Custom House Museum, the Mel Fisher Maritime Museum, and the Butterfly Conservatory are all air-conditioned half-days.
• Take the deal. Old Town guesthouse rates in September can be half the winter price — many regulars go every year and simply watch the forecast.

Better windows: when to visit instead

• April: The sweet spot — 26°C days, 12 hours of sun, 36mm of rain, the spring-break crowd gone by mid-month, and winter rates easing after Easter.
• Early November: Dry season is back (62mm), the water is still warm, and demand is low between Fantasy Fest and Thanksgiving. The best-value window.
• January – March:The most reliable weather, at peak prices. Book ahead for Christmas week and Presidents' Day.

Click any month on the seasonality map above for the full climate detail and our verdict.