All data are in degrees Fahrenheit

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Water temperature in Sullivans Island

Detailed information about the current water temperature in Sullivans Island. The trend over the last two weeks, daily averages, and precise forecast of the water temperature changes. Gain a deeper understanding of seasonal dynamics with monthly statistical analyses covering recent years.
Sea temperature in Sullivans Island now

84.7

°F

September 7, 02:35

Trend:

stable

Yesterday:

84.7°F

Tomorrow:

84.8°F

Sunrise:

06:58

Sunset:

19:37

Day Length:

12 h. 39 min.

Sullivans Island in September

Minimum:

48.2°F

Average:

55.6°F

Maximum:

63.1°F

Sea water temperature in Sullivans Island today

As of now, in Sullivans Island, the water temperature is 84.7°F. Swimming in water of this temperature is considered highly warm and would be enjoyable for everyone. At this temperature, you can comfortably engage in water-based activities for extended periods without experiencing discomfort. Today's reading is 2.6°F higher than the average recorded on this particular day in recent years. The sea temperature remains approximately unchanged from yesterday. According to the forecast, we expect the temperature to stay about the same.

Recent sea temperature and forecast

The water temperature today is above average for the last two weeks, showing a small increase in temperature. It is also close to the historical maximum temperature for this date. The maximum temperature recorded for this date was 85.5°F on 2020, while the historical minimum was 79.3°F on 2024.

The water temperature over the last two weeks displayed soome variability. While the two week average stayed close to the historical average, there were some days when the temperature was close to the maximum recorded over the past years. The forecast for the upcoming week shows a gradual cooling trend. The average temperature is expected to be 84.2°F, the minimum temperature may reach 83.9°F, and the maximum might stay at 84.8°F.

Daily water temperature in Sullivans Island

Date Current Year

actual* / forecast**

last year 10 years average
Aug 24 85.6°F 83.1°F 84.1°F
Aug 25 85.3°F 82.9°F 83.5°F
Aug 26 85.0°F 83.1°F 83.5°F
Aug 27 84.7°F 83.1°F 83.3°F
Aug 28 84.2°F 82.2°F 83.3°F
Aug 29 83.6°F 82.1°F 83.3°F
Aug 30 83.4°F 82.0°F 83.3°F
Aug 31 83.1°F 81.8°F 83.3°F
Sep 1 83.1°F 81.1°F 83.2°F
Sep 2 83.6°F 80.5°F 83.3°F
Sep 3 83.4°F 80.2°F 83.1°F
Sep 4 84.5°F 78.0°F 82.7°F
Sep 5 84.5°F 78.5°F 82.5°F
Sep 6 84.7°F 79.6°F 82.1°F
Sep 7 84.7°F 79.9°F 82.1°F
Sep 8 84.8°F 81.0°F 82.2°F
Sep 9 84.5°F 80.1°F 81.9°F
Sep 10 84.3°F 79.4°F 81.7°F
Sep 11 84.1°F 79.1°F 81.5°F
Sep 12 83.9°F 77.9°F 81.3°F
Sep 13 83.9°F 77.1°F 81.2°F
Sep 14 84.0°F 77.4°F 81.3°F

* actual - actual temperature values

** forecast - projected values for the next week

Real-time coastal temperatures could deviate by several degrees from the provided readings. These deviations often become evident following intense rainfall or strong winds.

Our forecasting methodology leverages a mathematical model, that uses current water and weather conditions, historical records, wind intensity and direction.

Sea water temperature in Sullivans Island by month

In Sullivans Island, the months May through October offer comfortable swimming conditions, which amounts to 155 swimming days.
The warmest water in Sullivans Island was recorded on August 22, 2026, reaching a 87.5°F. While the coldest temperature occurred on January 26, 2025, dipping to 44.1°F. The average readings by season are 55.9°F in Winter, 67.1°F in Spring, 82.8°F in Summer, and 73.5°F in Autumn.