Key West weather by month

Regulars are consistent this counts as genuinely pleasant overall, warm and sunny with little rain chance the norm, though several cold fronts each winter bring a handful of windy, noticeably chillier days, temperatures dropping 10-15 degrees below the run of the month. Our row backs that mild, still-dry read, 23.9C over 17.9C nights, with 46.9mm of rain across 5.2 days and a real 30.9 kph wind. Regulars are consistent this is high season here, prices climbing accordingly, jeans and a light sweater the standard packing advice for evenings and any cold-front days rather than a full coat. The sea sits at a swimmable 24.6C despite the water reading cooler than the air on paper. The record: humidity 77 percent, 9 hours of sun and AQI 45.

February in Key West is sunny and mostly dry - our row gives 41.4mm across 3.7 days - with an average high near 76F and a low near 66F, and most visitors getting 70s-to-80s days and cool nights. The word regulars repeat is windy. Our row's 28.6 kph is the strongest wind of the Key West year, and the consequences they list are the water ones: it is not a great month for water activities, and the wind is enough to make the ferry a poor bet. A cold front can also drop a couple of days into low-60s highs and low-50s nights, which is why the packing advice is shorts plus one sweatshirt. This is also peak season. The record: 26C days, 19.9C nights, 10.1 hours of sun and a 25.3C sea.

Key West's forum puts March highs in the low 80s°F with low humidity and little rain, though nights can still dip into the upper 60s. Regulars flag March as genuinely windy and note the water itself is still cool from winter, low 70s, so opinions are split on whether it's warm enough yet for comfortable swimming — pack a light windbreaker regardless.

April in Key West is a single planning question on the forum: which side of Easter are you on. The busiest weeks sit right around it, mostly families on spring vacation rather than a rowdy college crowd, and regulars say it thins out noticeably afterwards - late April is the sweet spot, with warm water and the crowds gone. The weather argument for the month is that the humidity has not come back yet and little falls. Wind is the one caveat they raise: April is reliably breezy, enough to spoil some days on the water, and sargassum turns up or does not depending on which way it is blowing. The record: 28.7C days feeling like 31C, 22.5C nights, 4.4 precipitation days, 11.6 hours of sun, a 27C sea and a 28 kph wind.

Regulars call this a transitional month rather than a settled one - awesome, un-oppressive weather in some years, hot and humid in others, with the one consistent change being winter's wind finally easing off, which makes it a favoured month for getting out on the water. Our row leans toward the warmer read, 30.2C reading as 34C at 77.1 percent humidity, over 24.1C nights, with 103.6mm of rain across 6.9 days. Regulars are specific about the calendar that follows: real humidity builds from late May, June brings the heat and the start of hurricane season in earnest, so May is the last easy month before both arrive. The sea stays calm and warm at 28.6C, good for fishing and snorkelling either way. The record: 11.9 hours of sun, a 25.7 kph wind and AQI 44.

Forum posters call September hot, humid and rainy, sitting right at the peak of hurricane season (which runs June-November, peaking late August into late September) - but they're consistent that actual disruption is rare. One repeat visitor of twenty consecutive Septembers reported being foiled by a hurricane only twice. The standard advice is simply to buy trip insurance and follow evacuation guidance if a storm does approach, not to avoid the month outright. The clear payoff for the hurricane-season gamble: genuine off-season pricing and noticeably lighter weekday crowds compared to the winter high season.

Key West-forum threads on November weather call it, along with October, one of the genuinely nice stretches of the year - warm days, cool nights, humidity down from summer's peak, closer in feel to spring than to the hurricane-season months just before it. Showers do still happen, but posters say it's rare for one to be more than something passing through rather than a washed-out day, and some stretches go by without a cloud in sight. The end of the month can turn unpredictable - a late-season storm or a couple of chillier days are possible - but the average still comes out ahead of what preceded it. High-season lodging rates don't kick in until mid-December, making early November good value too, alongside a couple of specific events in the first half of the month. The record: 27.3C days feeling like 29C, 21.9C nights, 68mm across 4.9 days, a 27.4C sea, 76 percent humidity, wind averaging over 29 km/h and 9.5 hours of sun.