Marine Weather and Tide Forecast for Marathon, FL
 | Sunrise 7:08 AM Sunset 7:47 PM Moonrise 2:17 AM Moonset 1:15 PM |
Marine Forecasts
NOTE: Zones were updated 3/20/2025. If your report is out of date, please click Edit
GMZ043 Expires:202604120245;;193057 Fzus52 Kkey 111437 Cwfkey
coastal waters forecast for the florida keys national weather service key west fl 1037 am edt Sat apr 11 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>044-120245- 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- 1037 am edt Sat apr 11 2026
.small craft advisory in effect - .
This afternoon - Northeast to east winds near 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. NEarshore waters rough. A slight chance of showers.
Tonight - Northeast to east winds near 20 knots. Seas 3 to 4 feet, occasionally to 5 feet, except 4 to 5 feet, occasionally to 6 feet west of cosgrove shoal light. NEarshore waters rough. A slight chance of showers.
Sunday through Monday - Northeast to east winds 20 to 25 knots. Seas 4 to 6 feet, occasionally to 8 feet. NEarshore waters very rough. A slight chance of showers.
Monday night - Northeast to east winds 20 to 25 knots, decreasing to near 20 knots. Seas 4 to 6 feet, occasionally to 8 feet. NEarshore waters very rough, becoming rough. A slight chance of showers.
Tuesday - East winds 15 to 20 knots. Seas 3 to 5 feet, occasionally to 6 feet. NEarshore waters choppy. A slight chance of showers.
Tuesday night - East winds 15 to 20 knots. Seas 3 to 5 feet, occasionally to 6 feet. NEarshore waters choppy.
Wednesday - East winds near 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. NEarshore waters a moderate chop.
Wednesday night - Northeast to east winds 15 to 20 knots. Seas 3 to 5 feet, occasionally to 6 feet. NEarshore waters choppy.
coastal waters forecast for the florida keys national weather service key west fl 1037 am edt Sat apr 11 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>044-120245- 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- 1037 am edt Sat apr 11 2026
GMZ005 Synopsis For Keys Coastal Waters From Ocean Reef To Dry Tortugas 1037 Am Edt Sat Apr 11 2026
Synopsis - A strong high pressure system over the eastern seaboard will maintain fresh to strong breezes through early next week. As is typical in this pattern for april, passing light fast-moving showers cannot be ruled out, especially in the overnight periods.
the approximate shoreward edge of the gulf stream as of april 10 - .
16 nm south of dry tortugas light - .on loggerhead key. 21 nm south of cosgrove shoal light - .off the marquesas keys. 23 nm south of sand key light - .off key west. 37 nm south of looe key - .off big pine key. 29 nm southeast of sombrero key light - .off marathon. 18 nm southeast of alligator reef light - .off islamorada. 13 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 10 - .
16 nm south of dry tortugas light - .on loggerhead key. 21 nm south of cosgrove shoal light - .off the marquesas keys. 23 nm south of sand key light - .off key west. 37 nm south of looe key - .off big pine key. 29 nm southeast of sombrero key light - .off marathon. 18 nm southeast of alligator reef light - .off islamorada. 13 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 Marathon, FL
NEW! Add second zone forecast
| Vaca Key-Fat Deer Key bridge Click for Map Sat -- 03:16 AM EDT Moonrise Sat -- 05:52 AM EDT 0.80 feet High Tide Sat -- 07:05 AM EDT Sunrise Sat -- 10:19 AM EDT 0.48 feet Low Tide Sat -- 02:14 PM EDT Moonset Sat -- 04:28 PM EDT 1.33 feet High Tide Sat -- 07:44 PM EDT Sunset Tide / Current data from XTide NOT FOR NAVIGATION |
Vaca Key-Fat Deer Key bridge, Florida, Tide feet
| 12 am |
| 0.1 |
| 1 am |
| 0.2 |
| 2 am |
| 0.4 |
| 3 am |
| 0.5 |
| 4 am |
| 0.7 |
| 5 am |
| 0.8 |
| 6 am |
| 0.8 |
| 7 am |
| 0.8 |
| 8 am |
| 0.7 |
| 9 am |
| 0.5 |
| 10 am |
| 0.5 |
| 11 am |
| 0.5 |
| 12 pm |
| 0.6 |
| 1 pm |
| 0.8 |
| 2 pm |
| 1 |
| 3 pm |
| 1.2 |
| 4 pm |
| 1.3 |
| 5 pm |
| 1.3 |
| 6 pm |
| 1.2 |
| 7 pm |
| 1.1 |
| 8 pm |
| 0.8 |
| 9 pm |
| 0.6 |
| 10 pm |
| 0.4 |
| 11 pm |
| 0.2 |
| Moser Channel Click for Map Flood direction 346 true Ebb direction 164 true Sat -- 02:11 AM EDT 0.00 knots Slack Sat -- 03:17 AM EDT Moonrise Sat -- 05:56 AM EDT 0.85 knots Max Flood Sat -- 07:06 AM EDT Sunrise Sat -- 08:37 AM EDT -0.00 knots Slack Sat -- 12:07 PM EDT -0.84 knots Max Ebb Sat -- 02:15 PM EDT Moonset Sat -- 02:31 PM EDT 0.00 knots Slack Sat -- 04:37 PM EDT 0.69 knots Max Flood Sat -- 07:40 PM EDT -0.00 knots Slack Sat -- 07:45 PM EDT Sunset Sat -- 11:01 PM EDT -1.24 knots Max Ebb Tide / Current data from XTide NOT FOR NAVIGATION |
Moser Channel, between Molasses and Pigeon Keys (depth 3 ft), Florida Current, knots
| 12 am |
| -1 |
| 1 am |
| -0.7 |
| 2 am |
| -0.1 |
| 3 am |
| 0.4 |
| 4 am |
| 0.7 |
| 5 am |
| 0.8 |
| 6 am |
| 0.8 |
| 7 am |
| 0.7 |
| 8 am |
| 0.3 |
| 9 am |
| -0.2 |
| 10 am |
| -0.6 |
| 11 am |
| -0.8 |
| 12 pm |
| -0.8 |
| 1 pm |
| -0.7 |
| 2 pm |
| -0.3 |
| 3 pm |
| 0.3 |
| 4 pm |
| 0.6 |
| 5 pm |
| 0.7 |
| 6 pm |
| 0.6 |
| 7 pm |
| 0.3 |
| 8 pm |
| -0.2 |
| 9 pm |
| -0.7 |
| 10 pm |
| -1.1 |
| 11 pm |
| -1.2 |
FXUS62 KKEY 111730 AFDKEY
Area Forecast Discussion National Weather Service Key West FL 130 PM EDT Sat Apr 11 2026
New AVIATION
KEY MESSAGES
- High confidence breezy to windy conditions will last through the weekend, and into the start of next week. A Small Craft Advisory remains in effect for all Florida Keys coastal waters.
- While passing showers will be possible in the fresh to strong easterlies, rainfall will be generally light, with little measurable amounts.
- Moderate drought conditions continue across the Keys. The minimal rainfall totals over the next seven days will support continued moderate drought conditions.
AVIATION
(18Z TAFS)
Issued at 128 PM EDT Sat Apr 11 2026 VFR conditions will prevail at both EYW and MTH through the TAF period. Some light showers are possible but not expected to impact either terminal at this time, therefore no mention of VCSH at either terminal. Near surface winds will continue to be easterly with gusts of near 25 knots.
PREVIOUS DISCUSSION
Issued at 600 AM EDT Sat Apr 11 2026 Surface analysis places a 1026 mb high pressure system centered over the Eastern Seaboard. This feature, interacting with a weak frontal boundary extending from the western Caribbean northeastward to the central North Atlantic, continues to support fresh to strong northeast to east breezes across the Florida Keys and the adjacent nearshore and offshore marine zones. KBYX Doppler radar is detecting isolated nocturnal showers owed to the moisture fluxes across the now near 80F surface temperature waters, although nearly all showers are light in nature. Current surface temperatures are in the lower 70s across the Island Chain at this early Saturday morning hour.
A rather stagnant and mundane forecast is in store for the next seven days across the Keys. The aforementioned high pressure system will slowly migrate eastward into the west-central North Atlantic over the next several days. The associated ridge axis will remain well north of the Florida Keys, supporting continued breezy to windy conditions. Isolated showers will be slightly favored in the overnight and early morning hours, although total rainfall amounts will generally be light. Moderate drought conditions will likely continue ahead of the upcoming wet season.
Temperatures will be at or just above normal through the end of the work week, with highs in the lower 80s, and lows in the lower 70s.
MARINE
Issued at 1136 AM EDT Sat Apr 11 2026 A Small Craft Advisory is in effect for all of the Florida Keys waters. From synopsis, a strong high pressure system over the Eastern Seaboard will maintain fresh to strong breezes through early next week. As is typical in this pattern for April, passing light fast-moving showers cannot be ruled out, especially in the overnight periods.
KEY WATCHES/WARNINGS/ADVISORIES
FL...None.
GM...Small Craft Advisory until 5 AM EDT Sunday for GMZ031>035- 042>044-052>055-072>075.
Area Forecast Discussion National Weather Service Key West FL 130 PM EDT Sat Apr 11 2026
New AVIATION
KEY MESSAGES
- High confidence breezy to windy conditions will last through the weekend, and into the start of next week. A Small Craft Advisory remains in effect for all Florida Keys coastal waters.
- While passing showers will be possible in the fresh to strong easterlies, rainfall will be generally light, with little measurable amounts.
- Moderate drought conditions continue across the Keys. The minimal rainfall totals over the next seven days will support continued moderate drought conditions.
AVIATION
(18Z TAFS)
Issued at 128 PM EDT Sat Apr 11 2026 VFR conditions will prevail at both EYW and MTH through the TAF period. Some light showers are possible but not expected to impact either terminal at this time, therefore no mention of VCSH at either terminal. Near surface winds will continue to be easterly with gusts of near 25 knots.
PREVIOUS DISCUSSION
Issued at 600 AM EDT Sat Apr 11 2026 Surface analysis places a 1026 mb high pressure system centered over the Eastern Seaboard. This feature, interacting with a weak frontal boundary extending from the western Caribbean northeastward to the central North Atlantic, continues to support fresh to strong northeast to east breezes across the Florida Keys and the adjacent nearshore and offshore marine zones. KBYX Doppler radar is detecting isolated nocturnal showers owed to the moisture fluxes across the now near 80F surface temperature waters, although nearly all showers are light in nature. Current surface temperatures are in the lower 70s across the Island Chain at this early Saturday morning hour.
A rather stagnant and mundane forecast is in store for the next seven days across the Keys. The aforementioned high pressure system will slowly migrate eastward into the west-central North Atlantic over the next several days. The associated ridge axis will remain well north of the Florida Keys, supporting continued breezy to windy conditions. Isolated showers will be slightly favored in the overnight and early morning hours, although total rainfall amounts will generally be light. Moderate drought conditions will likely continue ahead of the upcoming wet season.
Temperatures will be at or just above normal through the end of the work week, with highs in the lower 80s, and lows in the lower 70s.
MARINE
Issued at 1136 AM EDT Sat Apr 11 2026 A Small Craft Advisory is in effect for all of the Florida Keys waters. From synopsis, a strong high pressure system over the Eastern Seaboard will maintain fresh to strong breezes through early next week. As is typical in this pattern for April, passing light fast-moving showers cannot be ruled out, especially in the overnight periods.
KEY WATCHES/WARNINGS/ADVISORIES
FL...None.
GM...Small Craft Advisory until 5 AM EDT Sunday for GMZ031>035- 042>044-052>055-072>075.
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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