textproduct: Key West

KEY MESSAGES

- Measurable rain chances will remain low through today through early next week, at generally 10% or less.

- Conditions will remain seasonably warm and muggy, but we may see heat index values above 105F, particularly along the Upper Keys, through Monday.

- A pocket of Saharan Air currently near and north of Hispaniola will slowly move west across our area starting Monday and could linger through Wednesday.

DISCUSSION

Issued at 1020 PM EDT Sun Jun 21 2026 Summertime conditions welcomed the solstice across the Florida Keys today. The KBYX radar detected a couple of attempts at a weak cloud line northwest of the Lower Keys late in the afternoon, but those showers collapsed rather quickly. The 00Z KKEY sounding provides a hint as to why, a sampled environmental PWAT about halfway between the 25th and 50th daily percentile values. GOES East nighttime microphysics observations indicate mostly clear skies in the lower levels across the Keys. Occasional high altitude cirrus clouds will be able to interrupt any stargazing attempts, but at this time the coverage does not appear sufficient to cut off radiational cooling along the larger islands. The drier environment aloft is not reflective of how it feels at the surface, sadly, as dew points across the island chain are stuck in the mid 70s. Breezes along the reef were even able to slacken to a couple periods of light and variable winds. In the current environment, persistence is the most apt word to describe the forecast. Even though the PWAT is lower in terms of climatology, it's still late June. Showers can still develop and any boundary collisions could be enough to set off short lived heavy showers. Opting to not change the forecast package as a result.

MARINE

Issued at 1020 PM EDT Sun Jun 21 2026 There are no watches, warnings, or advisories in effect for the Florida Keys coastal waters. From synopsis, a broad, weak high pressure is centered over the Florida Peninsula. This will maintain a weakened pressure field across the Florida Keys and surrounding coastal waters. As a result, expect winds to be highly variable due to convection developing across South Florida and moving into our waters during the overnight hours. Thereafter the high will flux in strength, resulting in breezes periodically entering peaks and lulls.

AVIATION

(00Z TAFS) Issued at 1020 PM EDT Sun Jun 21 2026 VFR conditions will prevail at EYW and MTH for the TAF period. Near surface winds are expected to veer east to southeasterly before sunrise. Showers capable of generating MVFR CIGs or VIS may be able to form, but are not at high enough confidence to include in the TAFs.

PRELIMINARY POINT TEMPS/POPS

Key West 84 91 84 91 / 10 10 10 10 Marathon 83 90 84 90 / 20 10 10 10

KEY WATCHES/WARNINGS/ADVISORIES

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