Month-specific sea-surface temperature · Brazil

Arraial do Cabo Sea Temperature in September

21.7°C

71.1°F

In September, sea-surface temperature near Arraial do Cabo has a historical monthly average of 21.7°C. This is not the reading for any particular holiday date.

Across 2023–2025, the lowest and highest yearly September monthly means were 21.2–22.5°C. These are not daily extremes.

Previous month

August · 21.8°C

Change into September: -0.1°C

Next month

October · 21.9°C

Change into next month: +0.2°C

Can you swim or snorkel in Arraial do Cabo in September?

At 21.7°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.

Arraial do Cabo Sea Temperature: All 12 Months

Choose a month for available historical evidence, month comparisons and swim guidance. Missing history is clearly marked and never presented as a long-term normal.

January 24.3°C February 24.8°C March 25.3°C April 24.6°C May 23.6°C June 22.6°C July 22.1°C August 21.8°C September 21.7°C October 21.9°C November 22.7°C December 23.5°C

Data source and limitations

Source: Open-Meteo Marine API, MeteoFrance sea-surface temperature; 2023–2025. Marine model grid near -22.97, -42.03. 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.