Key West airport sets new daily warm low temperature record

Key West got almost no overnight relief as temperatures at Key West International Airport fell only to 84 degrees, setting a new daily warm low record and tying the month’s warm-low mark for May. For Monroe County, that means more than a weather footnote: the kind of persistent heat that raises cooling demand, strains outdoor workers and adds another sign of what local businesses face as peak tourism and hurricane season draw closer.

The National Weather Service said the 84-degree low on May 10, 2026, broke the old daily warm low record of 81 degrees, set in 2021. It also matched the monthly May warm-low record of 84 degrees, last reached on May 31, 2024. At the same station, the daytime high climbed to 90 degrees, tying the daily high record last set in 2024.

The record matters because nighttime temperatures are when homes, hotels and apartments normally get a break from the day’s heat. When the low stays in the mid-80s at the southernmost point in the continental United States, air conditioners have to work longer to bring indoor temperatures down, and the body gets less time to recover from daytime heat stress. That is especially important for construction crews, dock workers, landscapers and anyone spending long hours outdoors across Key West and the rest of the Florida Keys.

National Weather Service Key West forecasters said very warm and humid conditions were expected across the Keys, with highs approaching 90 degrees and moderate to fresh west-to-northwesterly breezes in the middle of the week. The agency’s climate records show that May’s warmest low in Key West is 84 degrees, underscoring how close the island city came to the top of the historical range.

Temperature records at Key West date to 1872, giving the latest reading a long historical frame. The weather service said the data are preliminary and remain subject to revision by NOAA’s National Centers for Environmental Information. Still, the combination of an 84-degree overnight low and a 90-degree afternoon high shows a stretch of heat that has immediate effects for households, employers and visitors alike as Monroe County moves deeper into the warm season.