textproduct: Key West

KEY MESSAGES

- Rain and thunder chances will only be slight (near 20%) through the rest of the weekend. - While highs will be seasonably warm in the upper 80s through next week, lows will remain warmer than normal, providing little relief from the heat in the overnight hours.

- The next opportunity for an uptick in active weather looks to be the middle of the week.

DISCUSSION

Issued at 509 AM EDT Sun May 31 2026 Our forecast area continues to sit under the periphery of high pressure extending across the area with fairly clam conditions during the overnight hours (we are not complaining). A few isolated showers tracked across the local waters, and crossed the island chain occasionally, but radar derived estimates suggest only a few hundredths of an inch may have been observed at any given island community. Conditions outside have continued to feel relatively gross as dew points sat in the mid to upper 70s. Coupled with overnight lows that were in the lower 80s, heat index values overnight were anywhere from near 90F in the Upper Keys to the mid 90s in the Lower Keys. We imagine sitting outside at night feels similar to sitting in a pot of water while waiting for it to come to a simmer. Due to the lack of temperature/dew point recovery overnight, this setup raises heat risk concerns with respect to anyone sensitive to the heat.

Muggy conditions will continue today as the pattern will see little change. Breezes will remain light and variable, but may assume a southwesterly direction for a short period of time in the afternoon due to daytime heating. This would offer an opportunity for reverse cloudline development. With weak steering flow, around 3 knots, this could result in a prolonged period of rainfall where any cloudline develops. All of this depends on whether on not southwesterlies prevail long enough to make this happen, so this is something that will have to be monitored in real time.

Guidance still points to a deep trough digging into Florida by the middle of the week, and sending a frontal boundary down the peninsula. Generally, this means an uptick in rain chances, but one caveat is the potential for some Saharan dust potentially arriving at the same time. Guidance may be overdoing rain chances over the middle of the week, specifically on Wednesday and Thursday, and it will be something to keep in mind as the forecast evolves.

MARINE

Issued at 509 AM EDT Sun May 31 2026 There are no watches, warnings, or advisories in effect for the Florida Keys local waters. From synopsis, weak high pressure across the area will support light to gentle southwesterly breezes over the next few days, becoming light and variable at times. Near normal rain and thunder chances also expected. A weak frontal boundary may stall near the Keys coastal waters by mid week, supporting an uptick in wind speeds as well as rain chances.

AVIATION

(06Z TAFS) Issued at 509 AM EDT Sun May 31 2026 VFR conditions will prevail through the TAF period, but occasional MVFR CIGs may be observed due to FEW clouds based at multiple levels between FL010 and FL030. Chances for rain near either terminal are near 20 percent, but there is low confidence with regard to timing. Opting to keep TAFs free of showers until timing becomes clearer. Light and variable surface winds will prevail.

CLIMATE

On this day in 2024, the daily record warm low temperature of 84F was recorded in Key West. This is also tied for the warmest low temperature ever recorded in May. Temperature records for Key West date back to 1872.

PRELIMINARY POINT TEMPS/POPS

Key West 89 82 89 81 / 20 10 20 0 Marathon 88 81 88 81 / 20 10 20 0

KEY WATCHES/WARNINGS/ADVISORIES

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