Marine Weather and Tide Forecast for Marathon, FL
April 23, 2025 3:56 AM EDT (07:56 UTC) Change Location
![]() | Sunrise 6:56 AM Sunset 7:54 PM Moonrise 3:00 AM Moonset 2:39 PM |
GMZ053 Expires:202504230830;;289330 Fzus52 Kkey 230230 Cwfkey
coastal waters forecast for the florida keys national weather service key west fl 1030 pm edt Tue apr 22 2025
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.
gmz052>055-072>075-230830- 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- 1030 pm edt Tue apr 22 2025
Overnight - East winds near 15 knots. Seas 3 to 5 feet, occasionally to 6 feet. Wave detail: east 4 feet at 5 seconds.
Wednesday - East winds near 15 knots. Seas 3 to 5 feet, occasionally to 6 feet. Wave detail: east 4 feet at 5 seconds.
Wednesday night - Northeast to east winds 15 to 20 knots. Seas 3 to 5 feet, occasionally to 6 feet. Wave detail: northeast to east 4 feet at 5 seconds.
Thursday - East winds 15 to 20 knots, increasing to near 20 knots. Seas 3 to 5 feet, occasionally to 6 feet. Isolated showers.
Thursday night - Northeast to east winds near 20 knots. Seas 4 to 6 feet, occasionally to 8 feet. Isolated showers.
Friday - East winds 15 to 20 knots. Seas 4 to 5 feet, occasionally to 6 feet. Isolated showers.
Friday night - Northeast to east winds 15 to 20 knots. Seas 4 to 5 feet, occasionally to 6 feet. Isolated showers.
Saturday - Northeast to east winds near 15 knots. Seas 3 to 5 feet, occasionally to 6 feet. Isolated showers.
Saturday night - Northeast to east winds near 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. Isolated showers.
Sunday - Northeast to east winds 10 to 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. Isolated showers.
Sunday night - Northeast to east winds 10 to 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. Isolated showers.
coastal waters forecast for the florida keys national weather service key west fl 1030 pm edt Tue apr 22 2025
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.
gmz052>055-072>075-230830- 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- 1030 pm edt Tue apr 22 2025
GMZ005 Synopsis For Keys Coastal Waters From Ocean Reef To Dry Tortugas 1030 Pm Edt Tue Apr 22 2025
Synopsis - Easterly breezes will be generally moderate, with winds slightly increasing over the night periods and slightly decreasing during the days as the surface high near the bahamas wobbles. Later this week, the high will restrengthen once again making for another round of fresh breezes as early as Thursday.
the approximate shoreward edge of the gulf stream as of april 22nd - .
30 nm south of dry tortugas light - .on loggerhead key. 6 nm south of cosgrove shoal light - .off the marquesas keys. 2 nm south of sand key light - .off key west. 4 nm south of looe key - .off big pine key. 5 nm south of sombrero key light - .off marathon. 7 nm southeast of alligator reef light - .off islamorada. 5 nm southeast of molasses reef light - .off key largo. 4 nm east 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.
the approximate shoreward edge of the gulf stream as of april 22nd - .
30 nm south of dry tortugas light - .on loggerhead key. 6 nm south of cosgrove shoal light - .off the marquesas keys. 2 nm south of sand key light - .off key west. 4 nm south of looe key - .off big pine key. 5 nm south of sombrero key light - .off marathon. 7 nm southeast of alligator reef light - .off islamorada. 5 nm southeast of molasses reef light - .off key largo. 4 nm east 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.
7 Day Forecast for Marine Location Near Marathon, FL

NEW! Add second zone forecast
Vaca Key-Fat Deer Key bridge Click for Map Wed -- 12:12 AM EDT 0.04 feet Low Tide Wed -- 04:00 AM EDT Moonrise Wed -- 06:23 AM EDT 1.10 feet High Tide Wed -- 06:54 AM EDT Sunrise Wed -- 12:06 PM EDT 0.27 feet Low Tide Wed -- 03:39 PM EDT Moonset Wed -- 06:08 PM EDT 1.43 feet High Tide Wed -- 07:50 PM EDT Sunset Tide / Current data from XTide NOT FOR NAVIGATION |   |
Vaca Key-Fat Deer Key bridge, Florida, Tide feet
12 am |
0 |
1 am |
0.1 |
2 am |
0.3 |
3 am |
0.5 |
4 am |
0.8 |
5 am |
1 |
6 am |
1.1 |
7 am |
1.1 |
8 am |
1 |
9 am |
0.8 |
10 am |
0.5 |
11 am |
0.3 |
12 pm |
0.3 |
1 pm |
0.3 |
2 pm |
0.6 |
3 pm |
0.8 |
4 pm |
1.1 |
5 pm |
1.3 |
6 pm |
1.4 |
7 pm |
1.4 |
8 pm |
1.2 |
9 pm |
0.9 |
10 pm |
0.6 |
11 pm |
0.3 |
Moser Channel (swingbridge) Click for Map Wed -- 03:22 AM EDT 0.00 knots Slack Wed -- 04:01 AM EDT Moonrise Wed -- 06:15 AM EDT 1.30 knots Max Flood Wed -- 06:55 AM EDT Sunrise Wed -- 09:19 AM EDT -0.00 knots Slack Wed -- 12:31 PM EDT -1.76 knots Max Ebb Wed -- 03:40 PM EDT Moonset Wed -- 03:45 PM EDT 0.00 knots Slack Wed -- 06:38 PM EDT 1.42 knots Max Flood Wed -- 07:50 PM EDT Sunset Wed -- 09:40 PM EDT -0.00 knots Slack Tide / Current data from XTide NOT FOR NAVIGATION |   |
Moser Channel (swingbridge), Florida Current, knots
12 am |
-1.8 |
1 am |
-1.6 |
2 am |
-1.1 |
3 am |
-0.3 |
4 am |
0.5 |
5 am |
1.1 |
6 am |
1.3 |
7 am |
1.2 |
8 am |
0.9 |
9 am |
0.3 |
10 am |
-0.6 |
11 am |
-1.3 |
12 pm |
-1.7 |
1 pm |
-1.7 |
2 pm |
-1.4 |
3 pm |
-0.7 |
4 pm |
0.2 |
5 pm |
1 |
6 pm |
1.4 |
7 pm |
1.4 |
8 pm |
1.2 |
9 pm |
0.6 |
10 pm |
-0.3 |
11 pm |
-1.2 |
Area Discussion for Key West, FL
Hide  HelpNOTE: mouseover dotted underlined text for definition
FXUS62 KKEY 230231 AFDKEY
Area Forecast Discussion National Weather Service Key West FL 1031 PM EDT Tue Apr 22 2025
New DISCUSSION, MARINE, AVIATION
DISCUSSION
Issued at 954 PM EDT Tue Apr 22 2025
A North Atlantic surface ridge stretches west southwestward across the far southeastern United States and Florida. This is maintaining gentle to moderate easterly breezes across the Keys and surrounding waters. Lower to mid level ridging remains near by and is helping in providing a stable and fairly dry atmosphere.
This evenings sounding indicated a very strong subsidence inversion based around 900 mb. Surface dew points are modest in the mid 60s with temperatures near 80. Satellite imagery through the evening depicted a very stable closed cell stratocumulus cloud field.
No synoptic changes are expected overnight. Ridging will remain dominant and maintain stable conditions. Expect winds to remain gentle to moderate out of the east. This steady flow will result in overnight lows settling in the mid to upper 70s with dew points remaining in the mid 60s. The rather low and strong synoptically forced inversion will preclude mention of showers.
MARINE
Issued at 954 PM EDT Tue Apr 22 2025
An Atlantic surface ridge will stretch across the Florida Peninsula overnight and maintain moderate easterly breezes on all Keys waters. Only minor changes made in the evening marine update.
AVIATION
(00Z TAFS)
Issued at 954 PM EDT Tue Apr 22 2025
VFR conditions will prevail at the island terminals through the overnight period. Surface winds will be gentle to moderate out of the east.
KEY WATCHES/WARNINGS/ADVISORIES
FL...None.
GM...None.
Area Forecast Discussion National Weather Service Key West FL 1031 PM EDT Tue Apr 22 2025
New DISCUSSION, MARINE, AVIATION
DISCUSSION
Issued at 954 PM EDT Tue Apr 22 2025
A North Atlantic surface ridge stretches west southwestward across the far southeastern United States and Florida. This is maintaining gentle to moderate easterly breezes across the Keys and surrounding waters. Lower to mid level ridging remains near by and is helping in providing a stable and fairly dry atmosphere.
This evenings sounding indicated a very strong subsidence inversion based around 900 mb. Surface dew points are modest in the mid 60s with temperatures near 80. Satellite imagery through the evening depicted a very stable closed cell stratocumulus cloud field.
No synoptic changes are expected overnight. Ridging will remain dominant and maintain stable conditions. Expect winds to remain gentle to moderate out of the east. This steady flow will result in overnight lows settling in the mid to upper 70s with dew points remaining in the mid 60s. The rather low and strong synoptically forced inversion will preclude mention of showers.
MARINE
Issued at 954 PM EDT Tue Apr 22 2025
An Atlantic surface ridge will stretch across the Florida Peninsula overnight and maintain moderate easterly breezes on all Keys waters. Only minor changes made in the evening marine update.
AVIATION
(00Z TAFS)
Issued at 954 PM EDT Tue Apr 22 2025
VFR conditions will prevail at the island terminals through the overnight period. Surface winds will be gentle to moderate out of the east.
KEY WATCHES/WARNINGS/ADVISORIES
FL...None.
GM...None.
Wind History for Vaca Key, FL
toggle option: (graph/table)
Airport Reports
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
Edit Hide
Key West, FL,

NOTICE: Some pages have affiliate links to Amazon. As an Amazon Associate, I earn from qualifying purchases. Please read website Cookie, Privacy, and Disclamers by clicking HERE. To contact me click HERE. For my YouTube page click HERE