Marine Weather and Tide Forecast for Duck Key, FL
 | Sunrise 7:01 AM Sunset 7:51 PM Moonrise 7:21 AM Moonset 9:38 PM |
Marine Forecasts
NOTE: Zones updated 4/16/2026. Some zones changed. Use Edit if needed.
GMZ043 Expires:202604200830;;654741 Fzus52 Kkey 192026 Cwfkey
coastal waters forecast for the florida keys national weather service key west fl 426 pm edt Sun apr 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.
wave detail will include details about the period and direction of origin for the highest energy waves. Long-period swells coming from a different direction than the wind would be included in the wave detail.
gmz042>044-200830- 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 pm edt Sun apr 19 2026
Tonight - Variable winds 5 to 10 knots, becoming north and increasing to near 10 knots. Seas around 1 foot, except building to 1 to 2 feet west of cosgrove shoal light. NEarshore waters smooth to a light chop, becoming a light chop. A slight chance of showers.
Monday - North to northeast winds near 10 knots, becoming northeast to east and increasing to 10 to 15 knots. Seas around 1 foot, building to 1 to 2 feet. West of cosgrove shoal light, seas 1 to 2 feet, building to 2 to 3 feet. NEarshore waters a light chop, becoming a light to moderate chop. A slight chance of showers and Thunderstorms.
Monday night - Northeast winds near 15 knots, increasing to 20 to 25 knots after midnight. Seas 1 to 2 feet, building to 3 to 4 feet, occasionally to 5 feet. West of cosgrove shoal light, seas 2 to 3 feet, building to 4 to 5 feet, occasionally to 6 feet. NEarshore waters a moderate chop, becoming very rough. A chance of showers with a slight chance of Thunderstorms.
Tuesday - Northeast to east winds near 25 knots. Seas 3 to 5 feet, occasionally to 6 feet, except 5 to 6 feet, occasionally to 8 feet west of cosgrove shoal light. NEarshore waters extremely rough. A slight chance of showers.
Tuesday night - Northeast to east winds near 25 knots, decreasing to 20 to 25 knots. Seas 4 to 6 feet, occasionally to 8 feet, except 5 to 7 feet, occasionally to 9 feet west of cosgrove shoal light. NEarshore waters extremely rough, becoming very rough.
Wednesday - East winds near 20 knots. Seas 3 to 5 feet, occasionally to 6 feet, except 4 to 6 feet, occasionally to 8 feet west of cosgrove shoal light. NEarshore waters rough.
Wednesday night - East winds near 20 knots, decreasing to 15 to 20 knots. Seas 3 to 5 feet, occasionally to 6 feet. NEarshore waters rough, becoming choppy. A slight chance of showers.
Thursday - East winds near 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. NEarshore waters a moderate chop. A slight chance of showers.
Thursday night - East winds near 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. NEarshore waters a moderate chop. A slight chance of showers.
Friday - East to southeast winds decreasing to 10 to 15 knots. Seas subsiding to 2 to 3 feet. NEarshore waters becoming a light to moderate chop. A slight chance of showers.
Friday night - East to southeast winds 10 to 15 knots. Seas 1 to 2 feet. NEarshore waters a light to moderate chop. A slight chance of showers.
coastal waters forecast for the florida keys national weather service key west fl 426 pm edt Sun apr 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.
wave detail will include details about the period and direction of origin for the highest energy waves. Long-period swells coming from a different direction than the wind would be included in the wave detail.
gmz042>044-200830- 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 pm edt Sun apr 19 2026
GMZ005 Synopsis For Keys Coastal Waters From Ocean Reef To Dry Tortugas 426 Pm Edt Sun Apr 19 2026
Synopsis - Generally light and variable winds early this evening will become gentle and northerly overnight ahead of an approaching front. This front is poised to sweep through the keys sometime Monday late afternoon/evening with a strong high pressure quickly filling in the wake on Tuesday. Fresh to strong breezes will develop as early as Monday night, and hazardous marine conditions will continue through at least mid week.
the approximate shoreward edge of the gulf stream as of april 16 - .
16 nm south of dry tortugas light - .on loggerhead key. 12 nm south of cosgrove shoal light - .off the marquesas keys. 22 nm south of sand key light - .off key west. 30 nm south of looe key - .off big pine key. 26 nm southeast of sombrero key light - .off marathon. 20 nm southeast of alligator reef light - .off islamorada. 15 nm southeast of molasses reef light - .off key largo. 9 nm southeast of carysfort reef light - .off ocean reef.
gulf stream information courtesy of the national weather service in key west based on products from nasa sport and rtofs.
the approximate shoreward edge of the gulf stream as of april 16 - .
16 nm south of dry tortugas light - .on loggerhead key. 12 nm south of cosgrove shoal light - .off the marquesas keys. 22 nm south of sand key light - .off key west. 30 nm south of looe key - .off big pine key. 26 nm southeast of sombrero key light - .off marathon. 20 nm southeast of alligator reef light - .off islamorada. 15 nm southeast of molasses reef light - .off key largo. 9 nm southeast of carysfort reef light - .off ocean reef.
gulf stream information courtesy of the national weather service in key west based on products from nasa sport and rtofs.
7 Day Forecast for Marine Location Near Duck Key, FL
NEW! Add second zone forecast
| Conch Key Click for Map Sun -- 04:06 AM EDT 0.18 feet Low Tide Sun -- 06:57 AM EDT Sunrise Sun -- 08:21 AM EDT Moonrise Sun -- 10:13 AM EDT 1.86 feet High Tide Sun -- 05:35 PM EDT -0.34 feet Low Tide Sun -- 07:47 PM EDT Sunset Sun -- 10:37 PM EDT Moonset Tide / Current data from XTide NOT FOR NAVIGATION |
Conch Key, eastern end, Florida, Tide feet
| 12 am |
| 1 |
| 1 am |
| 0.8 |
| 2 am |
| 0.5 |
| 3 am |
| 0.3 |
| 4 am |
| 0.2 |
| 5 am |
| 0.3 |
| 6 am |
| 0.6 |
| 7 am |
| 1 |
| 8 am |
| 1.4 |
| 9 am |
| 1.7 |
| 10 am |
| 1.9 |
| 11 am |
| 1.8 |
| 12 pm |
| 1.6 |
| 1 pm |
| 1.2 |
| 2 pm |
| 0.8 |
| 3 pm |
| 0.3 |
| 4 pm |
| -0.1 |
| 5 pm |
| -0.3 |
| 6 pm |
| -0.3 |
| 7 pm |
| -0.2 |
| 8 pm |
| 0.1 |
| 9 pm |
| 0.4 |
| 10 pm |
| 0.7 |
| 11 pm |
| 0.9 |
| Long Key Viaduct Click for Map Flood direction 349 true Ebb direction 170 true Sun -- 02:34 AM EDT -0.00 knots Slack Sun -- 05:04 AM EDT -1.38 knots Max Ebb Sun -- 06:57 AM EDT Sunrise Sun -- 08:13 AM EDT 0.00 knots Slack Sun -- 08:21 AM EDT Moonrise Sun -- 10:52 AM EDT 1.04 knots Max Flood Sun -- 02:10 PM EDT -0.00 knots Slack Sun -- 05:06 PM EDT -1.73 knots Max Ebb Sun -- 07:47 PM EDT Sunset Sun -- 08:25 PM EDT 0.00 knots Slack Sun -- 10:37 PM EDT Moonset Sun -- 11:29 PM EDT 1.31 knots Max Flood Tide / Current data from XTide NOT FOR NAVIGATION |
Long Key Viaduct, Florida Current, knots
| 12 am |
| 1.2 |
| 1 am |
| 0.9 |
| 2 am |
| 0.4 |
| 3 am |
| -0.3 |
| 4 am |
| -1.1 |
| 5 am |
| -1.4 |
| 6 am |
| -1.2 |
| 7 am |
| -0.8 |
| 8 am |
| -0.1 |
| 9 am |
| 0.5 |
| 10 am |
| 0.9 |
| 11 am |
| 1 |
| 12 pm |
| 0.9 |
| 1 pm |
| 0.6 |
| 2 pm |
| 0.1 |
| 3 pm |
| -0.6 |
| 4 pm |
| -1.4 |
| 5 pm |
| -1.7 |
| 6 pm |
| -1.5 |
| 7 pm |
| -1 |
| 8 pm |
| -0.3 |
| 9 pm |
| 0.4 |
| 10 pm |
| 1 |
| 11 pm |
| 1.3 |
FXUS62 KKEY 191848 AFDKEY
Area Forecast Discussion National Weather Service Key West FL 248 PM EDT Sun Apr 19 2026
New AVIATION
KEY MESSAGES
- Seasonable weather conditions are expected to continue through Monday, with mostly to partly sunny skies, near- average temperatures, and light to gentle breezes.
- A late-season cold front is expected to arrive Monday night, with potential showers and thunderstorms as well as fresh to strong breezes in its wake.
- Small Craft Advisory conditions look increasingly likely across Florida Keys coastal waters Monday night through Wednesday.
AVIATION
(18Z TAFS)
Issued at 239 PM EDT Sun Apr 19 2026 Cloud bases near FL020 will lead to flight categories flip flopping between VFR and MVFR for the first few hours of the TAF period due to a cloudline hugging the Lower and Middle Keys. This cloudline will also produce short lives, isolated pockets of very light rain, but opting to keep the current TAFs dry since they are dissipating so quickly. Crosswind concern is low, even with the northerly component, as surface winds are 5 to 10 knots through the period.
PREV DISCUSSION
Issued at 453 AM EDT Sun Apr 19 2026
A surface high that has seemingly been unmovable will finally shift eastward across the Atlantic and loosen its grip on the Florida Keys. This will leave us in a col region, resulting in light and variable winds developing during the morning and afternoon today. This will be brief as a cold front currently draped across the North Gulf coast will be making slow but steady progress southward over the next 24 to 48 hours.
Said cold front will sweep through Monday evening with a blast of northeasterlies. Windy conditions will develop in earnest overnight Monday and continue through Wednesday. A little better moisture will also accompany the front and it will be enough for some scattered showers and possible a few thunderstorms. Given the north to northeast steering flow on Monday, the first areas to see thunderstorms will be the Upper Keys and surrounding coastal waters immediately downwind of the mainland. As the front sweeps through, the remainder of the Keys will see a chance of thunderstorms.
Our chance at rain and any accumulations will unfortunately be limited to Monday evening as the front moves through. GFS and ECMWF have both come into agreement that the moisture plume with the front will slide well to our south. There remains a signal on Thursday for another shot at some rain as a potent upper level shortwave pivots southeast across the Gulf and over the Keys.
However, this will remain highly dependent on how much moisture we can recover prior to that feature arriving. Otherwise, there are no other discernible features that will make a noticeable dent in our moderate drought conditions within the next 5 - 7 days.
MARINE
Issued at 1100 AM EDT Sun Apr 19 2026 There are no watches, warnings, or advisories in effect for the Florida Keys local waters. From synopsis, the Florida Keys coastal waters will be situated under a col region this afternoon.
This will result in a period of light and variable winds lasting through the early evening. Breezes will freshen slightly Sunday night into Monday morning ahead of an approaching front. This front is poised to sweep through the Keys sometime Monday late afternoon/evening with a strong high pressure quickly filling in the wake on Tuesday. Fresh to strong breezes will develop as early as Monday night, and hazardous marine conditions will continue through at least mid week.
PRELIMINARY POINT TEMPS/POPS
Key West 84 74 84 72 / 10 10 10 20 Marathon 83 75 83 72 / 10 10 20 30
KEY WATCHES/WARNINGS/ADVISORIES
FL...None.
GM...None.
Area Forecast Discussion National Weather Service Key West FL 248 PM EDT Sun Apr 19 2026
New AVIATION
KEY MESSAGES
- Seasonable weather conditions are expected to continue through Monday, with mostly to partly sunny skies, near- average temperatures, and light to gentle breezes.
- A late-season cold front is expected to arrive Monday night, with potential showers and thunderstorms as well as fresh to strong breezes in its wake.
- Small Craft Advisory conditions look increasingly likely across Florida Keys coastal waters Monday night through Wednesday.
AVIATION
(18Z TAFS)
Issued at 239 PM EDT Sun Apr 19 2026 Cloud bases near FL020 will lead to flight categories flip flopping between VFR and MVFR for the first few hours of the TAF period due to a cloudline hugging the Lower and Middle Keys. This cloudline will also produce short lives, isolated pockets of very light rain, but opting to keep the current TAFs dry since they are dissipating so quickly. Crosswind concern is low, even with the northerly component, as surface winds are 5 to 10 knots through the period.
PREV DISCUSSION
Issued at 453 AM EDT Sun Apr 19 2026
A surface high that has seemingly been unmovable will finally shift eastward across the Atlantic and loosen its grip on the Florida Keys. This will leave us in a col region, resulting in light and variable winds developing during the morning and afternoon today. This will be brief as a cold front currently draped across the North Gulf coast will be making slow but steady progress southward over the next 24 to 48 hours.
Said cold front will sweep through Monday evening with a blast of northeasterlies. Windy conditions will develop in earnest overnight Monday and continue through Wednesday. A little better moisture will also accompany the front and it will be enough for some scattered showers and possible a few thunderstorms. Given the north to northeast steering flow on Monday, the first areas to see thunderstorms will be the Upper Keys and surrounding coastal waters immediately downwind of the mainland. As the front sweeps through, the remainder of the Keys will see a chance of thunderstorms.
Our chance at rain and any accumulations will unfortunately be limited to Monday evening as the front moves through. GFS and ECMWF have both come into agreement that the moisture plume with the front will slide well to our south. There remains a signal on Thursday for another shot at some rain as a potent upper level shortwave pivots southeast across the Gulf and over the Keys.
However, this will remain highly dependent on how much moisture we can recover prior to that feature arriving. Otherwise, there are no other discernible features that will make a noticeable dent in our moderate drought conditions within the next 5 - 7 days.
MARINE
Issued at 1100 AM EDT Sun Apr 19 2026 There are no watches, warnings, or advisories in effect for the Florida Keys local waters. From synopsis, the Florida Keys coastal waters will be situated under a col region this afternoon.
This will result in a period of light and variable winds lasting through the early evening. Breezes will freshen slightly Sunday night into Monday morning ahead of an approaching front. This front is poised to sweep through the Keys sometime Monday late afternoon/evening with a strong high pressure quickly filling in the wake on Tuesday. Fresh to strong breezes will develop as early as Monday night, and hazardous marine conditions will continue through at least mid week.
PRELIMINARY POINT TEMPS/POPS
Key West 84 74 84 72 / 10 10 10 20 Marathon 83 75 83 72 / 10 10 20 30
KEY WATCHES/WARNINGS/ADVISORIES
FL...None.
GM...None.
Wind History for Vaca Key, FL
toggle option: (graph/table)
Link to 1 hour of 5 minute data for KMTH
Terminal Aerodrome Forecast (TAF) for KMTH
Wind History Graph: MTH
(wind in knots)
GEOS Local Image of southeast
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Key West, FL,
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