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

67.7

°F

April 5, 10:17

Trend:

increasing

Yesterday:

66.3°F

Tomorrow:

68.1°F

Sunrise:

07:03

Sunset:

19:42

Day Length:

12 h. 39 min.

Sullivans Island in April

Minimum:

49.6°F

Average:

57.1°F

Maximum:

66.5°F

Sea water temperature in Sullivans Island today

As of now, in Sullivans Island, the water temperature is 67.7°F. Swimming in water of this temperature is seen as relatively warm and enjoyable for some individuals, although many might find it slightly too cool. Today's reading is 3.5°F higher than the average recorded on this particular day in recent years. Since yesterday, there was a noticeable increase in temperature. This indicates a warming trend over the past day. According to the forecast, we expect the temperature to rise a bit.

Recent sea temperature and forecast

Today's water temperature is notably higher than the average recorded over the past two weeks, indicating a significant warming trend. It is also close to the historical maximum temperature for this date. The maximum temperature recorded for this date was 67.9°F on 2023, while the historical minimum was 59.3°F on 2021.

Over the past two weeks, the water temperature has closely aligned with historical averages for those days. The forecast for the upcoming week suggests a gradual increase. The average temperature is expected to rise up to 68.7°F, with minimum temperature starting at 68.1°F, while the maximum might reach 69.1°F.

Daily water temperature in Sullivans Island

Date Current Year

actual* / forecast**

last year 10 years average
Mar 22 59.7°F 60.3°F 60.7°F
Mar 23 60.9°F 60.3°F 60.6°F
Mar 24 61.6°F 60.2°F 60.8°F
Mar 25 61.2°F 61.4°F 61.5°F
Mar 26 59.6°F 61.9°F 61.4°F
Mar 27 61.4°F 61.5°F 61.8°F
Mar 28 62.5°F 61.4°F 62.0°F
Mar 29 63.1°F 62.2°F 62.2°F
Mar 30 62.2°F 61.9°F 62.1°F
Mar 31 60.8°F 62.3°F 62.8°F
Apr 1 62.5°F 65.1°F 63.4°F
Apr 2 64.0°F 65.3°F 63.7°F
Apr 3 64.0°F 65.5°F 63.6°F
Apr 4 66.3°F 67.3°F 63.9°F
Apr 5 67.7°F 67.9°F 64.2°F
Apr 6 68.1°F 67.7°F 64.6°F
Apr 7 68.4°F 69.0°F 64.9°F
Apr 8 69.1°F 68.8°F 65.6°F
Apr 9 69.0°F 68.6°F 65.4°F
Apr 10 68.6°F 67.8°F 65.1°F
Apr 11 68.7°F 67.0°F 65.1°F
Apr 12 68.9°F 68.4°F 65.3°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 157 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 55.9°F in Winter, 67.1°F in Spring, 82.7°F in Summer, and 73.5°F in Autumn.