INSTRUMENT / SEA TEMPERATURE
Catalina Island Water Temperature
Updated Mon 13:50 (America/New_York)
USA · Forecast updated Nov 9, 2026, 13:50 UTC
Current Sea Temperature
24.1°C
75.4°F
Mild water
Valid Nov 9, 2026, 13:50 (America/New_York). Source: stored Open-Meteo marine forecast. Temperature is not a safety rating or snorkel score.
Versus this month's average
6.6°C above
The typical November average is 17.5°C (63.5°F) from the historical baseline.
Recent trend
Holding fairly steady
Seven-day average: 23.6°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 or replace the snorkel forecast.
Typical Sea Temperature Over the Year
In the historical baseline for Catalina Island, typical monthly averages range from about 14.4°C (57.9°F) in March to 21.2°C (70.2°F) in August.
Over the past 30 days, the average sea temperature in Catalina Island has been 22.8°C.
Historical baseline (full year)
Northern Hemisphere. Summer is generally June–August; winter is December–February.
Typical monthly sea-surface temperature near Catalina Island, calculated from hourly observations for 2022–2025. This is not this site's forecast archive.
| Month | Typical range | Average |
|---|---|---|
| January | 14.5–16.3°C | 15.1°C / 59.2°F |
| February | 14.0–15.3°C | 14.6°C / 58.3°F |
| March | 13.5–15.5°C | 14.4°C / 57.9°F |
| April | 14.8–15.3°C | 15.1°C / 59.2°F |
| May | 16.5–17.2°C | 16.8°C / 62.2°F |
| June | 17.7–19.3°C | 18.8°C / 65.8°F |
| July | 19.5–21.1°C | 20.3°C / 68.5°F |
| August | 20.8–21.7°C | 21.2°C / 70.2°F |
| September | 20.8–21.2°C | 21.0°C / 69.8°F |
| October | 19.6–19.8°C | 19.7°C / 67.5°F |
| November | 16.0–18.4°C | 17.5°C / 63.5°F |
| December | 15.4–17.0°C | 16.2°C / 61.2°F |
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature dataset. Nearest sea grid cell (33.38, -118.37). Each month is the mean of yearly monthly means; the range is the lowest and highest of those yearly monthly means. Open-Meteo methodology.
Water temperature by month
Each month uses the 2022–2025 baseline. The range is the lowest and highest yearly monthly mean, not an hourly extreme.
Catalina Island in January
Typical January water temperature near Catalina Island is 15.1°C (59.2°F), with yearly monthly means from 14.5–16.3°C.
Swimming and snorkeling: cold water. Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Adjacent months: December 16.2°C · February 14.6°C.
Explore Catalina Island sea temperature in January, including swim comfort and month comparisons →
Catalina Island in February
Typical February water temperature near Catalina Island is 14.6°C (58.3°F), with yearly monthly means from 14.0–15.3°C.
Swimming and snorkeling: cold water. Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Adjacent months: January 15.1°C · March 14.4°C.
Explore Catalina Island sea temperature in February, including swim comfort and month comparisons →
Catalina Island in March
Typical March water temperature near Catalina Island is 14.4°C (57.9°F), with yearly monthly means from 13.5–15.5°C.
Swimming and snorkeling: cold water. Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Adjacent months: February 14.6°C · April 15.1°C.
Explore Catalina Island sea temperature in March, including swim comfort and month comparisons →
Catalina Island in April
Typical April water temperature near Catalina Island is 15.1°C (59.2°F), with yearly monthly means from 14.8–15.3°C.
Swimming and snorkeling: cold water. Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Adjacent months: March 14.4°C · May 16.8°C.
Explore Catalina Island sea temperature in April, including swim comfort and month comparisons →
Catalina Island in May
Typical May water temperature near Catalina Island is 16.8°C (62.2°F), with yearly monthly means from 16.5–17.2°C.
Swimming and snorkeling: cold water. Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Adjacent months: April 15.1°C · June 18.8°C.
Explore Catalina Island sea temperature in May, including swim comfort and month comparisons →
Catalina Island in June
Typical June water temperature near Catalina Island is 18.8°C (65.8°F), with yearly monthly means from 17.7–19.3°C.
Swimming and snorkeling: cool water. A 3 mm shorty or full wetsuit will make longer snorkels more comfortable.
Adjacent months: May 16.8°C · July 20.3°C.
Explore Catalina Island sea temperature in June, including swim comfort and month comparisons →
Catalina Island in July
Typical July water temperature near Catalina Island is 20.3°C (68.5°F), with yearly monthly means from 19.5–21.1°C.
Swimming and snorkeling: cool water. A 3 mm shorty or full wetsuit will make longer snorkels more comfortable.
Adjacent months: June 18.8°C · August 21.2°C.
Explore Catalina Island sea temperature in July, including swim comfort and month comparisons →
Catalina Island in August
Typical August water temperature near Catalina Island is 21.2°C (70.2°F), with yearly monthly means from 20.8–21.7°C.
Swimming and snorkeling: cool water. A 3 mm shorty or full wetsuit will make longer snorkels more comfortable.
Adjacent months: July 20.3°C · September 21.0°C.
Explore Catalina Island sea temperature in August, including swim comfort and month comparisons →
Catalina Island in September
Typical September water temperature near Catalina Island is 21.0°C (69.8°F), with yearly monthly means from 20.8–21.2°C.
Swimming and snorkeling: cool water. A 3 mm shorty or full wetsuit will make longer snorkels more comfortable.
Adjacent months: August 21.2°C · October 19.7°C.
Explore Catalina Island sea temperature in September, including swim comfort and month comparisons →
Catalina Island in October
Typical October water temperature near Catalina Island is 19.7°C (67.5°F), with yearly monthly means from 19.6–19.8°C.
Swimming and snorkeling: cool water. A 3 mm shorty or full wetsuit will make longer snorkels more comfortable.
Adjacent months: September 21.0°C · November 17.5°C.
Explore Catalina Island sea temperature in October, including swim comfort and month comparisons →
Catalina Island in November
Typical November water temperature near Catalina Island is 17.5°C (63.5°F), with yearly monthly means from 16.0–18.4°C.
Swimming and snorkeling: cold water. Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Adjacent months: October 19.7°C · December 16.2°C.
Explore Catalina Island sea temperature in November, including swim comfort and month comparisons →
Catalina Island in December
Typical December water temperature near Catalina Island is 16.2°C (61.2°F), with yearly monthly means from 15.4–17.0°C.
Swimming and snorkeling: cold water. Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Adjacent months: November 17.5°C · January 15.1°C.
Explore Catalina Island sea temperature in December, including swim comfort and month comparisons →
Forecast archive (growing)
These values come from hourly forecasts SnorkelForecast has stored. They cover only months with records and do not replace the historical baseline.
| 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 | 22.4°C / 72.3°F | 23.5°C / 74.3°F | 25.1°C / 77.2°F |
| September | 21.6°C / 70.9°F | 22.7°C / 72.9°F | 24.2°C / 75.6°F |
| October | 21.4°C / 70.5°F | 22.7°C / 72.9°F | 24.5°C / 76.1°F |
| November | 22.7°C / 72.9°F | 23.7°C / 74.6°F | 24.4°C / 75.9°F |
Partial coverage: 6 calendar months with records. Profile calculated from 3886 hourly forecast records across 6 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 water temperature in Catalina Island today?
The current sea surface temperature near Catalina Island is 24.1°C (75.4°F). Over the last 30 days, the average has been 22.8°C.
When is the water warmest in Catalina Island?
The water is typically warmest in August, at around 21.2°C (70.2°F) in the 2022–2025 historical baseline.
When is the water coldest in Catalina Island?
The water is typically coldest in March, at around 14.4°C (57.9°F) in the same historical baseline. A wetsuit is usually recommended during this period.
Can you swim in Catalina Island today?
At 24.1°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 →