Key Biscayne — Water Temperature in December

Water Temperature Range

22°C

minimum

25°C

average

28°C

maximum

Get instant access to real-time water temperatures for this and all other locations with our iOS and Android apps.

Water Temperature Chart for Month

The chart shows the average daily water temperature for each day of the month based on historical data.

Table of Water Temperatures by Day of the Month for Previous Years

Day	2025	2024	2023	2022
DEC 1	26°C	25°C	26°C	25°C
DEC 2	25°C	24°C	26°C	24°C
DEC 3	25°C	25°C	25°C	25°C
DEC 4	25°C	24°C	26°C	25°C
DEC 5	25°C	25°C	25°C	26°C
DEC 6	25°C	24°C	24°C	26°C
DEC 7	25°C	25°C	25°C	26°C
DEC 8	26°C	26°C	25°C	26°C
DEC 9	25°C	27°C	25°C	25°C
DEC 10	25°C	26°C	25°C	25°C
DEC 11	25°C	25°C	24°C	24°C
DEC 12	25°C	26°C	24°C	24°C
DEC 13	25°C	25°C	24°C	25°C
DEC 14	25°C	25°C	24°C	24°C
DEC 15	24°C	25°C	22°C	24°C
DEC 16	24°C	25°C	22°C	24°C
DEC 17	24°C	24°C	23°C	23°C
DEC 18	24°C	23°C	23°C	24°C
DEC 19	24°C	23°C	24°C	23°C
DEC 20	24°C	24°C	25°C	23°C
DEC 21	24°C	24°C	25°C	24°C
DEC 22	25°C	24°C	24°C	24°C
DEC 23	24°C	24°C	23°C	24°C
DEC 24	24°C	23°C	22°C	24°C
DEC 25	24°C	24°C	23°C	23°C
DEC 26	24°C	24°C	23°C	24°C
DEC 27	24°C	24°C	22°C	23°C
DEC 28	24°C	25°C	23°C	24°C
DEC 29	24°C	24°C	24°C	24°C
DEC 30	24°C	24°C	23°C	24°C
DEC 31	24°C	25°C	23°C	24°C

December: Climate and Swimming Opportunities

Average Night Air Temperature

18°C

Average Day Air Temperature

24°C

Precipitation Amount per Month

50 mm

Number of Rainy Days

Daylight per Day

10 hrs

Sunshine per Day

7 hrs

Average Wind Speed

16 km/h

Average Humidity

74%

At such water and air temperatures, swimming feels truly comfortable and relaxing. The warm water won’t cool you down, so you can stay in for a long time without getting chilled.