Grand Cayman Sea Temperature

Updated Sat 15:16 (America/Cayman)

Cayman Islands · Forecast updated Aug 8, 2026, 15:16 UTC

Current Sea Temperature

30.5°C

86.9°F

Very warm water

Versus this month's average

Close to average

The August average in our archive is 30.5°C (86.9°F).

Recent trend

Cooling by 0.3°C

Seven-day average: 30.6°C, versus 30.9°C in the prior seven days.

What to wear

Very warm water

Swimwear is usually enough; a rash guard adds sun protection.

Cold tolerance varies. Wind, session length, sunshine, and exertion also affect comfort; temperature alone does not describe sea conditions.

Sea Surface Temperature Over the Year

In the data collected for Grand Cayman, monthly averages range from about 29.5°C (85.0°F) in June to 30.5°C (86.9°F) in August.

Over the past 30 days, the average sea temperature in Grand Cayman has been 30.3°C.

Month	Min	Average	Max
June	28.9°C / 84.0°F	29.5°C / 85.0°F	30.1°C / 86.2°F
July	29.6°C / 85.3°F	30.2°C / 86.3°F	31.4°C / 88.5°F
August	30.0°C / 86.0°F	30.5°C / 86.9°F	31.0°C / 87.8°F

Profile calculated from 1656 hourly forecast records across 3 monthly periods. This is a growing archive, not a long-term climate normal.

Home to Stingray City and the shallow coral gardens of the North Sound.

The current sea surface temperature in Grand Cayman is 30.5°C. Over the last 30 days, the average has been 30.3°C.

The warmest monthly average in the Grand Cayman archive is August, at around 30.5°C (86.9°F).

The coldest monthly average in the archive is June, at around 29.5°C (85.0°F).

At 30.5°C, the water is usually comfortable for swimming and snorkeling.

See how today's sea temperature, wave height, wind, and tides combine into a detailed snorkeling score for Grand Cayman.