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

73.5

°F

October 14, 01:24

Trend:

decreasing

Yesterday:

73.6°F

Tomorrow:

73.2°F

Sunrise:

07:22

Sunset:

18:48

Day Length:

11 h. 26 min.

Sullivans Island in October

Minimum:

49.3°F

Average:

56.6°F

Maximum:

63.1°F

Sea water temperature in Sullivans Island today

As of now, in Sullivans Island, the water temperature is 73.5°F. It's safe to say that the water is comfortably warm for various water-related activities. Today's reading is 1.5°F lower 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 fall a bit.

Recent sea temperature and forecast

Today's water temperature is considerably lower than the average registered over the last two weeks, indicating a slight cooling trend. It is also close to the historical minimum temperature for this date. The maximum temperature recorded for this date was 79.8°F on 2018, while the historical minimum was 72.3°F on 2022.

Over the past two weeks, the water temperature has closely aligned with historical averages for those days. The forecast for the upcoming week shows a gradual cooling trend. The average temperature is expected to be 72.1°F, the minimum temperature may reach 70.6°F, and the maximum might stay at 73.2°F.

Daily water temperature in Sullivans Island

Date Current Year

actual* / forecast**

last year 10 years average
Sep 30 79.8°F 80.1°F 79.2°F
Oct 1 79.0°F 80.0°F 78.9°F
Oct 2 78.2°F 80.0°F 78.4°F
Oct 3 76.3°F 79.6°F 77.8°F
Oct 4 75.7°F 79.4°F 77.5°F
Oct 5 75.4°F 79.1°F 77.2°F
Oct 6 74.7°F 78.7°F 76.9°F
Oct 7 76.0°F 77.3°F 76.6°F
Oct 8 75.9°F 77.8°F 76.5°F
Oct 9 75.4°F 77.7°F 76.2°F
Oct 10 75.3°F 77.3°F 75.9°F
Oct 11 74.9°F 75.7°F 75.6°F
Oct 12 74.2°F 73.6°F 75.2°F
Oct 13 73.6°F 72.5°F 75.1°F
Oct 14 73.5°F 72.9°F 75.0°F
Oct 15 73.2°F 73.8°F 74.7°F
Oct 16 72.8°F 72.1°F 74.3°F
Oct 17 72.9°F 71.0°F 74.4°F
Oct 18 72.6°F 70.6°F 74.1°F
Oct 19 71.7°F 68.7°F 73.2°F
Oct 20 70.9°F 67.8°F 72.4°F
Oct 21 70.6°F 67.1°F 72.1°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 156 swimming days.
The warmest water in Sullivans Island was recorded on August 1, 2025, reaching a 86.8°F. While the coldest temperature occurred on January 26, 2025, dipping to 44.1°F. The average readings by season are 56.9°F in Winter, 67.1°F in Spring, 82.7°F in Summer, and 73.7°F in Autumn.