National Weather Service Marine Forecast FZUS52 KKEY

FZUS52 KKEY 190826
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
426 AM EDT Sun Jul 19 2026

Florida Bay, Hawk Channel and Straits of Florida from Ocean Reef to south of Dry Tortugas, and the extreme southeastern Gulf of America, including The Florida Keys National Marine Sanctuary

Seas are given as significant wave height, which is the average height of the highest 1/3 of the waves. Individual waves may be more than twice the significant wave height.

The Wave Detail section highlights the period and direction of origin for the highest-energy waves, as well as any long-period swells moving in a different direction than the wind.

GMZ005-192030
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas 426 AM EDT Sun Jul 19 2026

SYNOPSIS
A broad area of low pressure over the eastern Gulf of America will shift northward through Monday, with prevailing gentle to moderate south to southeasterly breezes across Florida Keys coastal waters. An Atlantic high pressure ridge will extend to the Florida Peninsula for the next several days. Gentle southeasterly breezes are expected to prevail across Keys coastal waters Monday night through Thursday, with overnight surges and afternoon lulls.

The Approximate Shoreward Edge of the Gulf Stream as of July 17, 2026...

49 NM South of Dry Tortugas Light...on Loggerhead Key. 51 NM South of Cosgrove Shoal Light...off the Marquesas Keys. 38 NM South of Sand Key Light...off Key West. 22 NM South of Looe Key...off Big Pine Key. 13 NM South of Sombrero Key Light...off Marathon. 6 NM Southeast of Alligator Reef Light...off Islamorada. 2 NM Southeast of Molasses Reef Light...off Key Largo. 1 NM Southeast of Carysfort Reef Light...off Ocean Reef.

Gulf Stream Information Courtesy of the National Weather Service in Key West, using data from RTOFS and NASA SPoRT SST.

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GMZ031-192030
Florida Bay including Barnes Sound, Blackwater Sound, and Buttonwood Sound
426 AM EDT Sun Jul 19 2026

TODAY
Southeast to south winds near 15 knots, decreasing to near 10 knots. Bay waters a moderate chop, becoming a light chop. A slight chance of showers and thunderstorms.

TONIGHT
Southeast to south winds near 10 knots, increasing to near 15 knots after midnight. Bay waters a light chop, becoming a moderate chop. A slight chance of showers and thunderstorms.

MONDAY
Southeast to south winds 10 to 15 knots, becoming south and decreasing to near 10 knots. Bay waters a light to moderate chop, becoming a light chop. A slight chance of showers and thunderstorms.

MONDAY NIGHT
Southeast to south winds near 10 knots, becoming southeast and increasing to 10 to 15 knots after midnight. Bay waters a light chop, becoming a light to moderate chop.

TUESDAY
Southeast winds 10 to 15 knots, decreasing to near 10 knots. Bay waters a light to moderate chop, becoming a light chop.

TUESDAY NIGHT
East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop.

WEDNESDAY
East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop. A slight chance of showers and thunderstorms.

WEDNESDAY NIGHT
East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop.

THURSDAY
East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop. A slight chance of showers.

THURSDAY NIGHT
East winds 5 to 10 knots. Bay waters smooth to a light chop. A slight chance of showers and thunderstorms.

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GMZ032-035-192030
Bayside and Gulfside from Craig Key to west end of Seven Mile Bridge
Gulf of America from west end of Seven Mile Bridge to Halfmoon Shoal out to 5 Fathoms
426 AM EDT Sun Jul 19 2026

TODAY
Southeast to south winds near 15 knots, becoming south and decreasing to near 10 knots. Seas 1 to 2 feet. Nearshore waters a moderate chop, becoming a light chop. A chance of showers with a slight chance of thunderstorms.

TONIGHT
South winds near 10 knots, increasing to near 15 knots after midnight. Seas 1 to 2 feet. Nearshore waters a light chop, becoming a moderate chop. A chance of showers with a slight chance of thunderstorms.

MONDAY
South winds near 15 knots, decreasing to near 10 knots. Seas 1 to 2 feet. Nearshore waters a moderate chop, becoming a light chop. A slight chance of showers and thunderstorms.

MONDAY NIGHT
Southeast to south winds 5 to 10 knots, becoming southeast and increasing to 10 to 15 knots after midnight. Seas around 1 foot. Nearshore waters a light to moderate chop.

TUESDAY
Southeast winds 10 to 15 knots, decreasing to near 10 knots. Seas 1 to 2 feet. Nearshore waters a light to moderate chop, becoming a light chop.

TUESDAY NIGHT
East to southeast winds 5 to 10 knots. Seas around 1 foot. Nearshore waters smooth to a light chop.

WEDNESDAY
East to southeast winds near 10 knots. Seas around 1 foot. Nearshore waters a light chop. A slight chance of showers and thunderstorms.

WEDNESDAY NIGHT
East to southeast winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop.

THURSDAY
East to southeast winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop.

THURSDAY NIGHT
East winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop. A slight chance of showers and thunderstorms.

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GMZ042>044-192030
Hawk Channel from Ocean Reef to Craig Key out to the reef
Hawk Channel from Craig Key to west end of Seven Mile Bridge out to the reef
Hawk Channel from west end of Seven Mile Bridge to Halfmoon Shoal out to the reef
426 AM EDT Sun Jul 19 2026

TODAY
Southeast to south winds near 15 knots, decreasing to near 10 knots this afternoon. Seas 2 to 3 feet, subsiding to 1 to 2 feet. Nearshore waters a moderate chop, becoming a light chop. A slight chance of showers and thunderstorms.

TONIGHT
Southeast to south winds 5 to 10 knots, increasing to near 15 knots after midnight. Seas 1 to 2 feet, building to around 2 feet. Nearshore waters smooth to a light chop, becoming a moderate chop. A chance of showers with a slight chance of thunderstorms.

MONDAY
Southeast to south winds 10 to 15 knots, decreasing to near 10 knots. Seas around 2 feet. Nearshore waters a light to moderate chop, becoming a light chop. A slight chance of showers and thunderstorms.

MONDAY NIGHT
Southeast to south winds 5 to 10 knots, becoming southeast and increasing to 10 to 15 knots after midnight. Seas 1 to 2 feet, building to around 2 feet. Nearshore waters smooth to a light chop, becoming a light to moderate chop.

TUESDAY
Southeast winds 10 to 15 knots, decreasing to near 10 knots. Seas 2 to 3 feet. Nearshore waters a light to moderate chop, becoming a light chop.

TUESDAY NIGHT
East to southeast winds near 10 knots. Seas around 2 feet. Nearshore waters a light chop.

WEDNESDAY
East to southeast winds near 10 knots. Seas around 2 feet. Nearshore waters a light chop. A slight chance of showers and thunderstorms.

WEDNESDAY NIGHT
East winds 5 to 10 knots. Seas 1 to 2 feet. Nearshore waters smooth to a light chop.

THURSDAY
East to southeast winds 5 to 10 knots. Seas around 1 foot. Nearshore waters smooth to a light chop.

THURSDAY NIGHT
East winds 5 to 10 knots. Seas around 1 foot. Nearshore waters smooth to a light chop. A slight chance of showers and thunderstorms.

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GMZ052>055-072>075-192030
Straits of Florida from Ocean Reef to Craig Key out 20 NM
Straits of Florida from Craig Key to west end of Seven Mile Bridge out 20 NM
Straits of Florida from west end of Seven Mile Bridge to south of Halfmoon Shoal out 20 NM
Straits of Florida from Halfmoon Shoal to 20 NM west of Dry Tortugas out 20 NM
Straits of Florida from Ocean Reef to Craig Key 20 to 60 NM out
Straits of Florida from Craig Key to west end of Seven Mile Bridge 20 to 60 NM out
Straits of Florida from west end of Seven Mile Bridge to south of Halfmoon Shoal 20 to 60 NM out
Straits of Florida from Halfmoon Shoal to 20 NM west of Dry Tortugas 20 to 60 NM out
426 AM EDT Sun Jul 19 2026

TODAY
Southeast to south winds near 15 knots, decreasing to 5 to 10 knots. Seas 2 to 4 feet, occasionally to 5 feet, subsiding to 1 to 2 feet. Wave Detail: Southeast 3 feet at 5 seconds. A slight chance of showers and thunderstorms.

TONIGHT
Southeast to south winds 5 to 10 knots, increasing to 10 to 15 knots after midnight. Seas 1 to 2 feet, building to 2 to 3 feet. Wave Detail: East to southeast 2 feet at 5 seconds and west to northwest 1 foot at 5 seconds. A chance of showers with a slight chance of thunderstorms.

MONDAY
Southeast to south winds 10 to 15 knots, becoming southeast and decreasing to near 10 knots. Seas 2 to 3 feet, subsiding to 1 to 2 feet. Wave Detail: East to southeast 2 feet at 4 seconds. A slight chance of showers and thunderstorms.

MONDAY NIGHT
Southeast winds 5 to 10 knots, increasing to 10 to 15 knots after midnight. Seas 1 to 2 feet, building to 2 to 3 feet.

TUESDAY
East to southeast winds 10 to 15 knots, decreasing to near 10 knots. Seas 2 to 3 feet.

TUESDAY NIGHT
East winds near 10 knots, becoming east to southeast and increasing to 10 to 15 knots. Seas 2 to 3 feet. A slight chance of showers and thunderstorms.

WEDNESDAY
East to southeast winds near 10 knots. Seas around 2 feet.

WEDNESDAY NIGHT
East winds near 10 knots. Seas around 2 feet. A slight chance of showers.

THURSDAY
East winds 5 to 10 knots. Seas 1 to 2 feet.

THURSDAY NIGHT
East winds near 10 knots. Seas 1 to 2 feet. A slight chance of showers and thunderstorms.

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GMZ033-034-192030
Gulf of America from East Cape Sable to Chokoloskee 20 to 60 NM out and beyond 5 fathoms
Gulf of America including Dry Tortugas and Rebecca Shoal Channel
426 AM EDT Sun Jul 19 2026

TODAY
South winds near 15 knots, becoming south to southwest and decreasing to 10 to 15 knots. Seas 2 to 3 feet. Wave Detail: Southeast to south 2 feet at 4 seconds and northwest 1 foot at 5 seconds. A chance of showers with a slight chance of thunderstorms.

TONIGHT
South to southwest winds 10 to 15 knots, becoming south and increasing to near 15 knots. Seas 2 to 3 feet. Wave Detail: South 2 feet at 4 seconds. A chance of showers with a slight chance of thunderstorms.

MONDAY
South to southwest winds near 15 knots, decreasing to 10 to 15 knots. Seas 2 to 3 feet. Wave Detail: South to southwest 2 feet at 4 seconds. A slight chance of showers and thunderstorms.

MONDAY NIGHT
South to southwest winds 10 to 15 knots, becoming southeast to south and decreasing to near 10 knots. Seas 2 to 3 feet, subsiding to around 2 feet. A slight chance of showers and thunderstorms.

TUESDAY
Southeast to south winds 10 to 15 knots, decreasing to 5 to 10 knots in the afternoon. Seas around 2 feet, subsiding to around 1 foot.

TUESDAY NIGHT
Southeast winds 5 to 10 knots, becoming east to southeast. Seas around 1 foot.

WEDNESDAY
East to southeast winds 5 to 10 knots. Seas around 1 foot. A slight chance of showers and thunderstorms.

WEDNESDAY NIGHT
East to southeast winds 5 to 10 knots. Seas around 1 foot. A slight chance of showers.

THURSDAY
East to southeast winds 5 to 10 knots. Seas around 1 foot.

THURSDAY NIGHT
East winds 5 to 10 knots. Seas around 1 foot. A slight chance of showers and thunderstorms.

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MJV