The Florida Keys
Islamorada Water Temperature
The self-proclaimed Sportfishing Capital of the World.
Sea-surface temperature
Very warmHolding steady · last two weeks
That is about 2°F warmer than average for this time of year, and holding steady over the last two weeks. The November average here is 80°F.
Updated Saturday, November 7 — sea-surface temperature modeled for Islamorada by Open-Meteo.
For swimming
Very warm
Bath-warm. Pleasant, though it stops being much relief from the heat of the day.
For fishing
Hot — fish the edges of the day
Early and late is the play. Through the middle of the day fish drop into deeper channels and passes where there's moving water and more oxygen.
The last two weeks
| Date | Average |
|---|---|
| Oct 25 | 81.3°F |
| Oct 26 | 81.3°F |
| Oct 27 | 81.3°F |
| Oct 28 | 80.8°F |
| Oct 29 | 82°F |
| Oct 30 | 82.8°F |
| Oct 31 | 83.1°F |
| Nov 1 | 82.8°F |
| Nov 2 | 82.4°F |
| Nov 3 | 82.2°F |
| Nov 4 | 81.3°F |
| Nov 5 | 81.7°F |
| Nov 6 | 81.9°F |
| Nov 7 | 81.9°F |
Islamorada water temperature by month
Averaged from 3 years of daily sea-surface temperature (2023–2025). The range column is the coolest and warmest daily average recorded in that month over the period — a guide to how much any given year can differ, not a record high and low.
| Month | Range | Average |
|---|---|---|
JanJanuary Cool but comfortable | 69–78°F | 74°F |
FebFebruary Warm | 69–80°F | 75°F |
MarMarch Warm | 74–82°F | 78°F |
AprApril Warm | 77–83°F | 79°F |
MayMay Very warm | 79–90°F | 84°F |
JunJune Very warm | 83–90°F | 86°F |
JulJuly Bath water | 85–92°F | 88°F |
AugAugust Bath water | 85–92°F | 89°F |
SepSeptember Very warm | 85–90°F | 87°F |
OctOctober Very warm | 80–87°F | 83°F |
NovNovembernow Warm | 76–82°F | 80°F |
DecDecember Warm | 70–80°F | 76°F |
Warmest
89°FAugust
Coolest
74°FJanuary
Warmest on average in August at 89°F; coolest in January at 74°F.
The water at Islamorada
Islamorada earns its 'Sportfishing Capital' billing with a rare combination: world-class bonefish, permit, and tarpon on the flats, a healthy reef full of snapper, and quick access to the Gulf Stream for sailfish and mahi. The famous backcountry basins and channels hold tarpon nearly year-round. It's the flats-fishing heart of the Keys.
the backcountry & Hawk Channel
What moves the water temperature here
The Gulf shelf off this coast is shallow, which is why the water swings so much more between summer and winter than open ocean at the same latitude does. Shallow water heats fast and gives that heat up fast: a single strong winter cold front can pull the inshore bays several degrees down in a couple of days, while the beaches a mile offshore barely move. Wind direction matters too — a sustained offshore breeze can pull cooler water up from below and drop the beach temperature noticeably in a morning.
Inshore bays, canals and flats run warmer than the beach through the summer and colder through the winter, for the same reason. The reading above is for the open water at Islamorada; expect the back bays to be a few degrees either side of it depending on the season.
Common questions
- What is the water temperature at Islamorada right now?
- The water at Islamorada is currently about 82°F (28°C). The November average here is 80°F.
- Is the water warm enough to swim at Islamorada in November?
- November averages 80°F at Islamorada, which most people would call warm. About as good as it gets — warm enough to stay in for hours without getting chilled.
- When is the water warmest at Islamorada?
- August is the warmest month on average at 89°F, and January the coolest at 74°F. 11 months of the year average 75°F or above.
- Why does the water temperature change so quickly here?
- The Gulf shelf off this coast is shallow, so it heats and cools far faster than deep open ocean. A strong winter cold front can pull the inshore water down several degrees in a couple of days, and a sustained offshore wind can drop beach temperatures in a single morning by pulling cooler water up from below.