Florida Keys Sea Temperature in September

Looking to find out what the average sea water temperature in Florida Keys is for September? Find out what the lowest, highest, and average water temperatures are for Florida Keys over the past 10 years.

Average water temperature in Florida Keys for September

The average, high, and low temperatures below should help you if you can swim in the water in Florida Keys in September.

29.92° C

(85.85° F)

  • highest: 31.39° C (88.5° F)
  • lowest: 27.89° C (82.2° F)

This water temperature is comparable to that of a swimming pool, but it might be higher than most open water swimmers prefer for serious swimming. Make sure to drink plenty of water before and after swimming and don't wear a wetsuit to avoid overheating.

Water temperature range by day in September in Florida Keys

The chart below shows the range of low and high temperatures by day for the month of September in Florida Keys.

Water temperatures for September in Florida Keys in recent years

Day 2024 2023 2022 2021
1 0° C 30.26° C 30.99° C 29.74° C
2 0° C 29.78° C 31.03° C 29.69° C
3 0° C 30.09° C 30.97° C 29.79° C
4 0° C 29.6° C 31.05° C 30.1° C
5 0° C 29.85° C 31.11° C 30.13° C
6 0° C 29.95° C 31.07° C 30.12° C
7 0° C 30.18° C 31.09° C 30.2° C
8 0° C 30.21° C 30.97° C 30.28° C
9 0° C 30.39° C 30.72° C 30.57° C
10 0° C 30.61° C 30.73° C 30.74° C
11 0° C 30.76° C 30.82° C 30.94° C
12 0° C 30.93° C 30.86° C 31.02° C
13 0° C 31.01° C 30.76° C 30.91° C
14 0° C 31.11° C 30.63° C 30.32° C
15 0° C 31.12° C 30.55° C 30.2° C
16 0° C 31.2° C 30.55° C 30.14° C
17 0° C 31.24° C 30.24° C 29.99° C
18 0° C 31.23° C 29.95° C 30.38° C
19 0° C 31.22° C 29.88° C 30.44° C
20 0° C 31.14° C 29.96° C 30.38° C
21 0° C 30.95° C 30.08° C 30.36° C
22 0° C 30.8° C 30.13° C 30.16° C
23 0° C 30.65° C 30.3° C 30.42° C
24 0° C 30.33° C 30.47° C 30.4° C
25 0° C 30° C 30.51° C 30.4° C
26 0° C 30.09° C 30.5° C 30.5° C
27 0° C 30.01° C 30.4° C 30.53° C
28 0° C 29.95° C 29.87° C 30.2° C
29 0° C 30.13° C 28.69° C 30.22° C
30 0° C 29.98° C 28.37° C 30.17° C

Water temperature in September for locations near Florida Keys

Cudjoe Key

United States, North America

24.70 miles away

Ramrod Key

United States, North America

26.42 miles away

Big Pine Key

United States, North America

27.20 miles away

Sugarloaf Key

United States, North America

27.83 miles away

Data source and citation

Raw data for the calculations made to find the sea surface temperature in Florida Keys comes from the National Oceanic and Atmospheric Administration (NOAA) and their 1/4° daily Optimum Interpolation Sea Surface Temperature.

The water temperature data is constructed by combining observations from different platforms (satellites, ships, buoys, and Argo floats) on a regular global grid. A spatially complete sea surface temperature map is then built by interpolating to fill in gaps in the data.

If you'd like to use any of the information above in the format it is presented, please use the citation tool below.

  • "Florida Keys Sea Temperature in September". SeaTemperatures.net. Accessed on May 2, 2024. http://seatemperatures.net/north-america/united-states/florida-keys-september-temperature/.

  • "Florida Keys Sea Temperature in September". SeaTemperatures.net, http://seatemperatures.net/north-america/united-states/florida-keys-september-temperature/. Accessed 2 May, 2024

  • Florida Keys Sea Temperature in September. SeaTemperatures.net. Retrieved from http://seatemperatures.net/north-america/united-states/florida-keys-september-temperature/.