textproduct: Key West

KEY MESSAGES

- Very warm and humid conditions expected across the Florida Keys this week, and will lead to a moderate to high risk for heat related illnesses. - Rain and thunder chances have peaked, and will gradually decrease through the middle of the week.

- A period of on and off breezy conditions expected through tonight, and will help to mitigate some of the discomfort from warm overnight temperatures.

DISCUSSION

Issued at 440 AM EDT Mon May 18 2026

A pocket of relatively drier air moved in during the afternoon and evening on Sunday, and did not recover as well as we had hoped. Therefore, the coverage of showers has been underperforming, at least as the island chain is concerned. It remained quite active across the surrounding coastal waters, but unfortunately, very few of these showers passed over the Keys. Temperatures this hour remain in the lower 80s with dew points in the mid 70s. Thankfully, breezy conditions developed and have aided in at least taking the edge off the muggy conditions.

For today, additional moisture to our east should pivot in throughout the day today. This combined with an already accelerated flow, should help to smash any mesoscale boundaries out there, allowing for showers to increase in coverage again. This enhanced moisture pool will linger through tonight and gradually begin scouring out starting Tuesday. This will not be a fast process and rain chances will be slow to diminish through the week. Meanwhile, a high pressure near Bermuda will flatten over the next several days, weakening the pressure gradient through the end of the week. This will lead to generally a slackening of winds, though there will still be some peaks in the evenings at times.

By the end of the week we may have an easterly undulation move through the Bahamas and along the east coast of Florida, injecting more moisture back across the area, and subsequently rain chances. It's too far out to get our hopes up at this time.

MARINE

Issued at 440 AM EDT Mon May 18 2026

Moderate to fresh breezes prevail this morning and will continue through the overnight. Small Craft Exercise Caution headlines are in effect for all of the Florida Keys coastal waters. A high pressure near Bermuda will flatten starting Tuesday and the pressure gradient across the Keys will gradually lessen. This will lead to a gradual, but generally slackening of breezes through the week. We can still expect some nocturnal peaks at times, before breezes return to light to gentle by Thursday. Thereafter, breezes may freshen slightly as an easterly undulation moves across the Bahamas.

AVIATION

(06Z TAFS) Issued at 440 AM EDT Mon May 18 2026

VFR conditions are expected outside of any passing shower. East to southeast winds will remain breezy at times through the forecast period. Not expecting showers necessarily all day, however, confidence on when breaks will occur and for how long is very uncertain.

PRELIMINARY POINT TEMPS/POPS

Key West 91 80 91 80 / 40 40 40 30 Marathon 87 79 86 80 / 40 40 40 30

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...None.