Month-specific sea-surface temperature · USA
Catalina Island Sea Temperature in January
15.1°C
59.2°F
In January, sea-surface temperature near Catalina Island has a historical monthly average of 15.1°C. This is not the reading for any particular holiday date.
Across 2023–2025, the lowest and highest yearly January monthly means were 14.5–16.3°C. These are not daily extremes.
Previous month
December · 16.4°C
Change into January: -1.3°C
Next month
February · 14.6°C
Change into next month: -0.5°C
Can you swim or snorkel in Catalina Island in January?
At 15.1°C our temperature-only guide describes the water as cold water. Comfort depends on your cold tolerance, immersion time and wind. A historical average cannot determine whether conditions are safe on any given day.
Do you need a wetsuit?
Use a full 3-5 mm wetsuit and keep the session within your cold-water experience.
Which beach should you choose?
Look for a beach sheltered from the actual forecast waves and wind on your visit. Exposure, currents and entry conditions vary even where water temperatures are similar. Follow local warnings.
Check the current waves, wind and snorkeling forecast →
A live forecast does not predict a future January. Check again close to your trip.
Waves and wind: recorded-model conditions for January
These figures come from a separately modelled, date-specific wind/wave backfill, not the NOAA SST series. A single observed season is not a climatological likelihood or a guarantee of safe conditions.
Compare nearby coasts with their own evidence
| Coast | Morning | Afternoon | Period |
|---|---|---|---|
| Dry Tortugas | 31% | 30% | Jan 2026 |
| Looe Key | 36% | 43% | Jan 2026 |
| Bahia Honda | 46% | 47% | Jan 2026 |
| Key Largo | 61% | 63% | Jan 2026 |
A “calm hour” meets fixed modelled wave/wind thresholds; neither visibility nor local currents, entry conditions or actual beach safety is measured here. Periods may differ by coast.
Nearby places in January
Comparable historical averages from independent marine grid cells. Warmer water does not imply safe snorkeling.
- La Jolla Cove 15.0°C
Data source and limitations
Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature; 2023–2025. Marine model grid near 33.39, -118.42. Based on 3 yearly monthly means and 2166 recorded samples. Source methodology.
Modelled sea-surface temperatures do not establish underwater visibility, wildlife, calm currents or safe entry.