Key Largo Weather

key largo weather showing clouds over molasses tower

The Key Largo weather report is to help customers as a guide to diving and snorkeling conditions.  We take information feeds from several other Key Largo marine forecast websites in order to provide this information. We also use our vast knowledge of the weather in Key Largo to ensure we can be as accurate as we can so you have the best information available.

The diving and snorkeling in Key Largo is largely influenced by the prevailing weather conditions. Both wave height and visibility can be affected depending on wind speed and direction. The water temperature is largely influenced by the seasons but the weather conditions will also have an influence.

If you want an honest opinion of the weather do give us a call even if your not diving with us!  We do not take customers out on our boats if we do not think they are going to have a good time, we would rather cancel our trip than you have a bad time! For our latest reports for daily wind vis and water temp go to the captains comments for todays Key Largo weather.

Sources for up to date Key Largo weather forecasts

Current marine forecast NOAA website.  For John Pennekamp coral reef use the Hawk Channel listing.  For Spiegel and Duane use the listing for Straights of Florida.

We also use Windfinder to get a view of wind and wave height and this our favorite page that give a more pictorial view.

For a large view of the areas weather system why not try our friends at

Todays Key Largo Weather Forecast

This is todays weather as forecast by Windfinder for Molasses Reef

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Captains comment for todays Key Largo weather

Captain Michael says:

March 13 – Amazing calm weather for mid march! flat seas, low winds and great visibility. The water temperature remains the same at 75F but we are expecting it to start rising soon in Key Largo as we have seen recorded sea water temperatures of 80F in Key West this week.

An added bonus the Eagle Rays have arrived!!

March 14 – winds have come up a little today but the visibility is still amazing.

March 17 St Patricks day. – Visibility remains very good, we have some ocean swells that around a foot behind the reef. The water temperature has been recorded at 79F!

March 18 – Weather sunny with 1-2ft seas, a little current on the outside of Grecian water temp 76F. Visibilty is really nice and we saw more Eagle Rays today.

March 19 – Seas expected to be around 3 feet today so not a good day to be snorkeling. We have canceled our morning tours and are waiting for an update to the forecast at 10.30


* WHAT…Northeast winds 20 to 25 knots, and seas up to 7 to 8 feet across the Straits of Florida. * WHERE…Straits of Florida, Hawk Channel, Gulf waters including the Dry Tortugas, and Florida Bay. * WHEN…In Effect. * IMPACTS…A Small Craft Advisory means that wind speeds of 20 to 33 knots, or seas of 7 feet or greater, are expected to produce hazardous conditions for small craft. These hazardous conditions may result in poor vessel handling and steering response, broaching, overturned dinghies and kayaks, slips and falls on slippery decks, rub damage along docks and seawalls, swamped bows at reef tract mooring balls, and dragging anchors.


When reading the Key Largo weather report links bear in mind that there will be the occasional wave that is twice the predicted wave hight!

We stop running snorkel trips when the seas get over 3 feet as its not comfortable for our snorkelers in the water.

We stop running dive trips when the winds get over 20 knots as its not comfortable for our divers.

Small Craft Advisory

A Small Craft Advisory is issued by the National Weather Service as a warning when winds have reached dangerous speeds. Sustained wind speeds that govern the issuance of a Small Craft Advisory vary depending on geographical areas, but are generally between 20 and 33 knots. 

Key Largo Weather Monthly trends

January and February

Water temperature is around 70-75F.  We get windy days and some cold days where the air temperature can get to around 50F.  Visibility can be fantastic!  You will need to wear a wetsuit between 3mm and 7mm. Hoods or hats are also a good idea.  Bring a waterproof with you to wear on the boat to help stop the windchill between dives.

March and April

Water temperature is around 75F-80F air is around 80F-85F. Wind can effect some days trips. 3mm wetsuits are best. We can get the odd cold day.

May and June

Great months for diving with water around 85F and air 88F. Wetsuits now optional. Visibility good at 50 to 60 feet. Humidity rises.

July and August

The water 85F+ and air temperatures 85F+ are warmest during these months and its also hurricane season. We track the hurricane situation daily via NOAA. You can dive in shorts and rash guard or exposure suit durning this time. Winds tend to die down and we start to see the Atlantic looking like a lake. Visibility is often over 80 feet

September and October

Water and Air temperature remain high and September remains high for hurricane watch but seas start to cool. 

September is peak hurricane season and we use Mikes Weather page to check out predictions!

November and December

The threat of hurricanes diminishes as the seas start to cool. Wetsuits come back out with 3mm usually being ok. Visibility is good.