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

71.9

°F

May 12, 14:06

Trend:

stable

Yesterday:

72.6°F

Tomorrow:

72.2°F

Sunrise:

06:23

Sunset:

20:09

Day Length:

13 h. 46 min.

Sullivans Island in May

Minimum:

48.3°F

Average:

56.6°F

Maximum:

63.8°F

Sea water temperature in Sullivans Island today

As of now, in Sullivans Island, the water temperature is 71.9°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 1.1°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 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 also falls within the range of the average temperature recorded for this date, suggesting a consistent weather trend. The maximum temperature recorded for this date was 75.6°F on 2019, while the historical minimum was 70.7°F on 2020.

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 minimum recorded over the past years. The forecast for the upcoming week suggests a gradual increase. The average temperature is expected to rise up to 72.8°F, with minimum temperature starting at 72.2°F, while the maximum might reach 73.8°F.

Daily water temperature in Sullivans Island

Date Current Year

actual* / forecast**

last year 10 years average
Apr 28 69.8°F 72.8°F 69.7°F
Apr 29 68.4°F 72.1°F 70.4°F
Apr 30 70.0°F 72.4°F 70.6°F
May 1 69.4°F 71.6°F 71.0°F
May 2 69.7°F 72.7°F 71.2°F
May 3 69.5°F 72.9°F 71.6°F
May 4 68.5°F 73.2°F 72.2°F
May 5 68.1°F 74.1°F 72.3°F
May 6 69.7°F 75.2°F 72.8°F
May 7 70.1°F 74.5°F 72.9°F
May 8 71.7°F 74.5°F 72.8°F
May 9 71.0°F 74.4°F 72.6°F
May 10 71.3°F 74.3°F 72.5°F
May 11 72.6°F 74.3°F 72.4°F
May 12 71.9°F 74.8°F 72.9°F
May 13 72.2°F 74.7°F 73.2°F
May 14 72.2°F 74.2°F 73.2°F
May 15 72.3°F 75.0°F 73.4°F
May 16 72.5°F 75.2°F 73.6°F
May 17 73.1°F 76.0°F 74.2°F
May 18 73.3°F 74.9°F 74.4°F
May 19 73.8°F 77.5°F 74.9°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.