textproduct: Key West

KEY MESSAGES

-Breezes will sharply increase tonight after a cold frontal passage. Windy conditions are expected to prevail through at least Monday morning.

-Cooler and drier conditions tonight and Monday. Overnight lows are expected to be 50 to 55 degrees across the Upper Keys and upper 50s for the Lower Keys.

-Chances of showers are expected this afternoon, and isolated thunderstorms are possible in the Straits and Hawk Channel. Slight chances of showers remain tonight.

-A period of breezy to windy conditions is anticipated for the early to middle part of this week.

AVIATION

(18Z TAFS) Issued at 1249 PM EST Sun Jan 18 2026 Prevailing MVFR conditions at both EYW and MTH will give way to IFR CIGs during a cold frontal passage between 18 and 21Z. Showers ahead of the cold front are capable of moderate to heavy rainfall and TEMPO LIFR CIGs. The approaching cold front may bring periods of LIFR CIGs amidst fast moving showers. After frontal passage, near surface winds will rapidly increase to near 20 knots with gusts near 30 knots. Winds will also back northwesterly, so crosswinds will be a concern for both EYW and MTH.

FORECAST

The Keys remain in a weak col region for this morning. This will lead to continued light and variable breezes for the next few hours before becoming west to northwest and rapidly freshening heading into the afternoon hours. Moisture remains plentiful across the Keys early this morning with isolated to scattered showers anticipated throughout the day. Latest guidance shows decent instability, moisture, along with a lifting mechanism being the cold front approaching the Keys today. Therefore, isolated thunder was added to Straits of Florida for today. Rain chances are 50% for the Middle and Upper Keys and 40% for the Lower Keys.

The aforementioned cold front in the discussion section above will continue moving towards the Keys today. The front is expected to pass through sometime during the afternoon hours. This will result in sharply freshening breezes out of the north. Frequent gusts of 25 to 30 knots or 30 to 35 mph are anticipated. In the wake of the front, windy conditions will continue along with a return to much cooler, drier, and less humid conditions. Overnight lows are expected to be 50 to 55 degrees in the Middle and Upper Keys with upper 50s for the Lower Keys. Monday will remain rather cool with daytime high struggling to get out of the mid to upper 60s. As Florida ever so subtly warms up Monday, this will act to weaken the breezes slightly Monday afternoon before picking back up again Monday evening. Therefore, don't be surprised if Monday afternoon isn't as windy as the morning hours.

An expansive high pressure system will then move across the eastern United States. This will keep the breezes elevated for much of the week with breezy to windy conditions all but certain for Monday night through at least Wednesday night. Moisture will remain scarce with most of the shower activity, if any, remaining across the Straits, at least initially. Once we approach mid week, the moisture is expected to creep northward bringing slight chances back into the forecast along the Island Chain. Latest guidance is suggesting this moisture becoming even deeper than originally though leading to chances now in the forecast for mid to late week. Temperatures and dew points will also slowly moderate through the week. Expect temperatures to be back to slightly above normal to above normal by late in the week.

Latest numerical and statistical guidance is hinting at another front late week into next weekend. Latest indications though are for this one to stall across the Keys leading to perhaps just a wind shift change with barely any change in dew points. Stay tuned!

MARINE

Issued at 444 AM EST Sun Jan 18 2026 A Small Craft Advisory is in effect for all nearshore and offshore waters of the Florida Keys. From synopsis, a cold front is currently draped across Georgia/Florida Panhandle extending southwestward through the Gulf and into the Bay of Campeche. This front is progged to push through the Florida Keys coastal waters later this afternoon. Breezes will sharply increase behind the passage of the cold front late today becoming fresh to strong, potentially near gale across the SE Gulf and westernmost Straits. In the wake of the front, an expansive high pressure system will then move across the eastern United States. This will continue to promote fresh to strong breezes through the week.

CLIMATE

On this day in Keys Weather History, in 1987, the daily record warm low temperature of 75F was recorded in Key West. Temperature records for Key West date back to 1872.

PRELIMINARY POINT TEMPS/POPS

Key West 58 65 60 72 / 10 0 0 0 Marathon 55 64 60 70 / 10 0 0 0

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...Small Craft Advisory until 5 AM EST Monday for GMZ031>035- 042>044-052>055-072>075.