World Resorts USA Siesta Key Weather

Siesta Key sea water temperature

Current sea water temperature:
+69.3°F
Minimum sea water temperature in December: 74.3°F
Maximum sea water temperature in December: 61.2°F
Average sea water temperature in December: 68.0°F

Sea water temperature for the last 10 days:

December 4 69.3°F November 29 70.9°F
December 3 70.0°F November 28 73.2°F
December 2 70.0°F November 27 73.0°F
December 1 69.4°F November 26 72.7°F
November 30 69.6°F November 25 72.1°F

When is the warmest sea in Siesta Key?

Based on the data about daily sea water temperature for the last three years the warmest sea in Siesta Key was noticed in August, July and September.

Monthly Sea Temperatures in Siesta Key, °F

Sea water temperature in August, °F

Show year:
2025
2024
2023

The average sea water temperature in August of 2025 was 88.6°F. The highest and lowest sea temperatures during the month were 90.1°F and 86.7°F.

Sea water temperature in July, °F

Show year:
2025
2024
2023

The average sea water temperature in July of 2025 was 86.9°F. The highest and lowest sea temperatures during the month were 89.1°F and 85.6°F.

Sea water temperature in September, °F

Show year:
2025
2024
2023

The average sea water temperature in September of 2025 was 84.9°F. The highest and lowest sea temperatures during the month were 86.7°F and 83.3°F.

Best time for vacation in Siesta Key

Sunniest months:
March 20 days
May 18 days
April 17 days
Warmest months:
July 88.1 °F
August 88.0 °F
June 86.3 °F
Warmest sea temp:
August 87.6 °F
July 87.1 °F
September 85.8 °F
Coldest months:
January 66.6 °F
December 70.1 °F
February 71.0 °F
Rainiest months:
June 5 days
July 4 days
September 3 days
Windiest months:
November 10.5 mph
January 10.4 mph
October 10.4 mph

Siesta Key on a weather map

Siesta Key
+64°F
W 4 mph
Feels like: +64°F
Precip.: 0%
Places in USA:
Name
°F
+30°F
+77°F
+77°F
+45°F
+55°F
+70°F
+77°F
+70°F
+25°F
+57°F
+48°F
+63°F
+63°F
+46°F
+5°F
24 Hours Forecast
Siesta Key
Local time: 00:15
December 05, friday
0300
63°F
W
6 mph
0600
63°F
NW
7 mph
0900
66°F
N
7 mph
1200
70°F
N
12 mph
1500
72°F
N
11 mph
1800
72°F
N
7 mph
2100
72°F
N
7 mph
December 06, saturday
0000
72°F
NE
6 mph
Units of measurement: °C / °F