textproduct: Key West

KEY MESSAGES

- Measurable rain chances will remain low through the weekend, only up to 10% for each forecast period.

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

DISCUSSION

Issued at 956 PM EDT Thu Jun 18 2026 It has been another calm, yet muggy, evening along the Florida Keys! Automated observations are reporting temperatures in the mid 80s, but dew points are in the upper 70s. This is how "air you can wear" is made. The lack of temperature recovery during the overnight hours is resulting in moderate heat risk concerns. Shortly after the 00Z KKEY sounding was launch, the radiosonde reported a stark inversion in the lower levels, and this has likely kept any activity from initiating this evening. This overall benign pattern, albeit gross, is courtesy of high pressure extended across our area, and this means . GOES-19 Cloud Top imagery shows a broken cirrus blanket across the area. It may be enough to prevent star gazing, but it also may be enough to prevent radiational cooling.

Even though our KBYX radar has been void of showers within our forecast area, we will opt to keep our inherited slight chance, 10%, of showers and thunderstorms. It's summertime in Florida, so you could consider this 10% our emotional support PoPs. Since the forecast is unfolding as expected, there are no changes proposed at this time. Stay cool.

MARINE

Issued at 956 PM EDT Thu Jun 18 2026 There are no watches, warnings, or advisories in effect for the Florida Keys waters. From synopsis, a weak high pressure system in the central North Atlantic will support a brief cycle of peaks and lulls over the next day or so. Then a weak frontal boundary will approach the Florida Peninsula, acting to weaken the high, and supporting a return to light to gentle breezes. Breezes may become light and variable at times, Sunday through Monday, especially across the nearshore and offshore waters north of the island chain.

AVIATION

(00Z TAFS) Issued at 956 PM EDT Thu Jun 18 2026 VFR conditions will prevail at both island terminals through the TAF period with only FEW clouds near FL020 and a SCT to BKN high deck near FL250. Weather is expected to remain dry, so the TAF package will reflect this, but a very low, near 10 percent, chance for rain remains in the general forecast. Will incorporate VCSH or RA if it becomes necessary.

PRELIMINARY POINT TEMPS/POPS

Key West 89 84 89 84 / 10 10 10 10 Marathon 88 84 88 84 / 10 10 10 10

KEY WATCHES/WARNINGS/ADVISORIES

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