Month-specific sea-surface temperature · Ecuador

San Cristóbal Sea Temperature in September

21.8°C

71.2°F

In September, sea-surface temperature near San Cristóbal has a historical monthly average of 21.8°C. This is not the reading for any particular holiday date.

Across 2023–2025, the lowest and highest yearly September monthly means were 19.9–24.4°C. These are not daily extremes.

Previous month

August · 22.2°C

Change into September: -0.4°C

Next month

October · 22.5°C

Change into next month: +0.7°C

Can you swim or snorkel in San Cristóbal in September?

At 21.8°C our temperature-only guide describes the water as cool 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?

A 3 mm shorty or full wetsuit will make longer snorkels more comfortable.

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 September. Check again close to your trip.

Nearby places in September

Comparable historical averages from independent marine grid cells. Warmer water does not imply safe snorkeling.

Data source and limitations

Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature; 2023–2025. Marine model grid near -0.90, -89.61. Based on 3 yearly monthly means and 2160 recorded samples. Source methodology.

Modelled sea-surface temperatures do not establish underwater visibility, wildlife, calm currents or safe entry.