Catalina Island Sea Temperature
Updated Mon 05:50 (America/New_York)
USA · Forecast updated Aug 10, 2026, 05:50 UTC
Current Sea Temperature
23.5°C
74.3°F
Mild water
Versus this month's average
0.3°C below
The August average in our archive is 23.8°C (74.8°F).
Recent trend
Warming by 0.3°C
Seven-day average: 23.7°C, versus 23.4°C in the prior seven days.
What to wear
Mild water
A rash guard is useful; cold-sensitive snorkelers may prefer a shorty wetsuit.
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 Catalina Island, monthly averages range from about 20.1°C (68.3°F) in June to 23.8°C (74.8°F) in August.
Over the past 30 days, the average sea temperature in Catalina Island has been 22.6°C.
Monthly Water Temperature Averages
| Month | Min | Average | Max |
|---|---|---|---|
| June | 19.1°C / 66.4°F | 20.1°C / 68.3°F | 21.5°C / 70.7°F |
| July | 19.6°C / 67.3°F | 21.5°C / 70.7°F | 24.1°C / 75.4°F |
| August | 23.0°C / 73.4°F | 23.8°C / 74.8°F | 24.5°C / 76.1°F |
Profile calculated from 1694 hourly forecast records across 3 monthly periods. This is a growing archive, not a long-term climate normal.
About the water at Catalina Island
Lover's Cove and Casino Point reserve offer clear-water kelp snorkeling off LA.
- Area
- California
Catalina Island Water Temperature: Common Questions
What is the sea temperature in Catalina Island today?
The current sea surface temperature in Catalina Island is 23.5°C. Over the last 30 days, the average has been 22.6°C.
When is the water warmest in Catalina Island?
The warmest monthly average in the Catalina Island archive is August, at around 23.8°C (74.8°F).
When is the water coldest in Catalina Island?
The coldest monthly average in the archive is June, at around 20.1°C (68.3°F).
Can you swim in Catalina Island today?
At 23.5°C, the water is usually comfortable for swimming and snorkeling.
Full Snorkeling Forecast
See how today's sea temperature, wave height, wind, and tides combine into a detailed snorkeling score for Catalina Island.
View Snorkel Forecast →