Marine Weather and Tide Forecast for Key West, FL

DISCUSSION
Issued at 430 AM EST Sat Feb 28 2026

Light to gentle southeast to southerly breezes are being driven by the western end of an Atlantic ridge stretching across South Florida and the Keys. This flow has brought in a warm and moisture rich airmass. Temperatures remain in the mid 70s with dew points in the lower 70s. While there is some veering, very low level inhibition and lower to mid level dry air has shut out shower activity near the island chain.

Over the course of the day, troughing moving through the eastern United States and associated weak lower level troughing developing across the peninsula will push out the surface ridge.
This along with day time heating will help to relax breezes as they clock southwesterly. Low level inhibition and limited lower to mid level moisture will help to keep rain chances minimal.
There is considerable uncertainty regarding fog potential late today into tonight. Surface dew points are expected to fall into the upper 60s overnight with the northerly flow. This along with water temperatures near or slightly below 70 on our gulf waters should provide a window for fog and low ceilings across portions of the Middle and Lower Keys.

The lower level trough across Florida will lift out to the northeast tonight as modest surface ridging expands southeastward from the southeastern United States. This will help to firm up northeasterly breezes. Winds coming in out of the northern half of the compass will help nudge dew points down further into the mid 60s. Temperatures should remain slightly above normal with highs in the upper 70s to near 80 and lows near 70.

A lengthy stretch of near breezy or breezy conditions are expected to set in heading into mid week as a beefy anticyclone builds southeastward off of northeastern North America. Breezes will begin trending upwards late Sunday and remain moderate to fresh through much of the week. These moderate to fresh breezes will gradually clock further east northeasterly to east over the ensuing days as the high builds out into the Atlantic. Expect a fairly static pattern through much of the week with highs near 80, lows near 70, and dew points in the upper 60s. The fast flow and deepening boundary layer should result in slight to low chance for showers.

MARINE
Issued at 430 AM EST Sat Feb 28 2026

The western end of an Atlantic ridge will retreat eastward today as troughing becomes better established across the Florida Peninsula. Light southerly breezes will shift north late today, remaining light. The trough will wash out tonight as modest ridging builds in from the southeastern United States. This will tip light breezes northeasterly overnight. Through the week, a broad high cell will drive southeastward off of northeastern North America and ramp up the local pressure gradient. Expect steadily freshening northeast to easterly breezes through the first half of the week, and linger through much of the week. A mix of cautions and advisories may be required for Keys waters from

AVIATION
(06Z TAFS)
Issued at 430 AM EST Sat Feb 28 2026

VFR conditions should prevail at both island terminals through the TAF period, but there is some uncertainty related to fog developing nearby in the afternoon. For now, we will keep SCT sky conditions near FL010 in case fragments of low clouds approach either airport, but any category reductions in the TAF package will have to wait until fog actually forms. Rain chances are virtually zero, and winds will remain light at the surface.

CLIMATE
The month of February in 1944 was the driest February on record for Key West with only a trace of rain recorded. Rainfall records for Key West date back to January of 1871. The month of February in 1955 was the driest February on record for Marathon with only a trace of rain recorded. Rainfall records for Marathon date back to June of 1950.

KEY WATCHES/WARNINGS/ADVISORIES
FL...None.
GM...None.