textproduct: Key West

KEY MESSAGES

- Measurable rain chances look to peak tonight, then gradually decreasing through Sunday night and into Monday.

- Conditions will remain seasonably warm and muggy.

- There will be little relief in the warm temperatures overnight, with minimum temperatures near record values in the lower to mid 80s for most communities.

MARINE

Issued at 251 PM EDT Sat Jun 27 2026

The Florida Keys are currently in a lull in terms of convection. Isolated showers and thunderstorms lie just on the edge of our coastal waters but are struggle to maintain and move into our area. This will likely change this evening and overnight as any additional convection across the southern Mainland spills into the extreme Southeast Gulf waters. At the same time, expect better moisture to surge east to west across the remaining coastal waters, allowing for a higher coverage of showers and thunderstorms tonight. Outside of convection, expect light to gentle east to southeast breezes to freshen overnight and then lull once again during the morning and afternoon hours on Sunday. This peak and lull cycle will persist into Monday evening, before a frontal boundary stalls across central Florida starting late Monday. This will weaken the high across our area and allow for a brief slackening of winds.

A weak, broad area of lower pressure may develop along this boundary sometime Wednesday into Thursday and could slightly freshen breezes once again.

AVIATION

(18Z TAFS) Issued at 251 PM EDT Sat Jun 27 2026

VFR conditions expected through the afternoon and evening. Moisture will return in earnest overnight, resulting in scattered showers and thunderstorms. For now have added mentions of VCSH after 06Z/Sunday and will leave mentions of TS for future amendments if needed.

PREV DISCUSSION

Issued at 518 AM EDT Sat Jun 27 2026

Another typical midsummer night has unfolded and moving into another summer morning! Observations across the island chain indicate temperatures are in the mid 80s with dewpoints holding steady in the mid 70s, maintaining a moist and muggy tropical airmass. Nighttime Microphysics satelitte imagery shows mostly clear skies with periodic scattered lower cumulus clouds embedded in our easterly flow. Marine locations are reporting easterly winds near 10 knots along the Reef, reflecting a modest pressure gradient from broad high pressure system in the North Atlantic. Scattered showers and thunderstorms from earlier in the night have dwindled down with KBYX detecting only a few sprinkles in the distant Straits.

Looking ahead, little change is expected through early next week as the Atlantic high pressure continues to dominate the regional pattern and maintains east to southeast flow through the period. Breezes will slightly freshen in the afternoon with diurnal mixing and then will return to light to gentle breezes by this evening. High temperatures will near 90, with the elevated mid 70 dewpoints heat index values will approach but stay just beneath Heat Advisory criteria. Rain chances will be near normal for this time of year again today with 30% supporting isolated to scattered showers and thunderstorms. Overall the weather will continue to be similar to previous days as no synoptic changes are anticipated.

PRELIMINARY POINT TEMPS/POPS

Key West 83 92 84 92 / 40 30 10 10 Marathon 83 89 84 89 / 40 30 10 10

KEY WATCHES/WARNINGS/ADVISORIES

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