textproduct: Key West

KEY MESSAGES

- A Coastal Flood Statement remains in effect, and particularly low lying areas will see some saltwater ponding around the times of high tide.

- A weak frontal passage is expected across the Keys sometime tonight/early Tuesday. This will lead to slightly cooler temperatures, a slight drop in dew points, and increased shower chances.

FORECAST

Ridging will continue to dominate the Keys today as we remain on the southern side of an approaching frontal boundary to the north. CIMSS Mimic TPW- Total Precipitable Water products shows a narrow plume of high moisture content to the north of the Keys in association with the front. We remain far enough south of this plume for today to warrant only slight chance PoPs. However, as this slides southward for tonight, PoPs will increase across the region to 40% or chances. We expect mainly showers for the Chain on north with the best chance of any thunderstorm activity being just south of the Chain across the Straits of Florida. Winds will also remain light to gentle and mostly out of the northeast through the period. Since we are ahead of the front, today will once again be quite warm with highs in the upper 80s and dew points in the mid to upper 70s. This will cause heat index values to hover around 100 degrees perhaps a couple degrees over. Make sure to take breaks and stay hydrated when outdoors for extended periods of time.

The cold front draped across the Florida Peninsula will make its move tonight and press through the Keys stalling somewhere across the Straits or close to Cuba. Initially, rain chances will decrease some, however, the moisture will be very close by, therefore, the drop in PoPs will be short-lived before increasing yet again by mid week. The initial expected drop in dew points doesn't look to be all that impressive now with perhaps dew points falling another degree or two maybe 3 (into the lower to mid 70s) from where they currently are early this morning. It should still feel better than it has the last couple days when dew points were practically 80 degrees. Since the front will remain nearby, it is expected to keep the Keys unsettled for much of the mid to late week period with increased rain chances, muggier conditions, and continued quite warm overnight lows considering we are basically in mid-October.

Numerical and global model guidance has been all over the place in regards to this front for the weekend. We recommend continuing to check back for updates as we get closer as it has the potential to be a rather rigorous front. The details remain very fuzzy and we will end this right here.

MARINE

Issued at 425 AM EDT Mon Oct 12 2026 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, a couple of nearby features will define the weather across the Florida Keys for the first half of the week. The Atlantic Ridge is gradually weakening and moving east towards the central Atlantic. Another weak high pressure system is located over the Gulf. Between the two pressure systems lies a weak frontal boundary that is set up across central Florida. The front is primed to pass across the Keys waters sometime early in the week, and promote gentle to moderate northeast to east breezes. Shower chances are forecast to be slight before mid-week before the previously mentioned front stalls near the Keys waters. Late in the week, there is a chance a strong cold front could develop and move towards the Florida Keys. Frontal passage with this cold front could occur over next weekend, and we will continue monitoring this system.

AVIATION

(06Z TAFS) Issued at 425 AM EDT Mon Oct 12 2026 VFR conditions are expected to persist at both EYW and MTH terminasl through the TAF period. Near surface winds will remain mostly northeast through the period. There remains the risk for a passing shower or thunderstorm throughout the period for either or both terminals. However, due to the timing and uncertainty, VCSH was not included at this time. The best chance for any activity appears to be during the overnight hours into early Tuesday morning.

CLIMATE

On this day in 2023, the daily record warm low temperature of 85F was recorded in Key West. This is also the warmest low temperature ever recorded during the month of October. Temperature records for Key West date back to 1872. Also, on this day in 2023, the daily record warm low temperature of 84F was recorded in Marathon. This is also tied for the warmest low temperature ever recorded during the month of October for the Marathon area. Temperature records for Marathon date back to 1951.

OF NOTE In 1987, Tropical Storm Floyd intensified into a Category 1 Hurricane as it moved east northeast between Cuba and the Keys. It traveled along the length of the Keys causing only minimal damage (with the exception of an F1 tornado near Rock Harbor on the 11th), with the eye passing directly over Key West bringing about an hour of "total calm" to the city.

PRELIMINARY POINT TEMPS/POPS

Key West 89 80 87 79 / 10 40 20 20 Marathon 89 80 87 79 / 20 40 20 20

KEY WATCHES/WARNINGS/ADVISORIES

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