Best Time to Dive Rio de Janeiro
Across 3 Rio de Janeiro dive sites with multi-year conditions history, May, June and December historically show the most favorable days — 100% of sampled days in the good band. The next-highest months are February (99%), January (98%) and July (98%). September historically shows the fewest favorable days (70% of sampled days). Average water temperature in the sample runs from about 22°C in August to 27°C in March. Typical seas range from 0.8 m to 1.2 m of significant wave height through the year. These figures are historical climatology computed from measured conditions — patterns, not a forecast or a guarantee.
Computed from our own conditions climatology — measured history, not brochure copy.
Which months are historically most favorable in Rio de Janeiro?
| Month | Historically favorable days | Water temp | Typical seas |
|---|---|---|---|
| Jan | 98% | 26°C | 0.8 m |
| Feb | 99% | 27°C | 0.8 m |
| Mar | 97% | 27°C | 0.8 m |
| Apr | 97% | 26°C | 0.9 m |
| May | 100% | 25°C | 0.9 m |
| Jun | 100% | 23°C | 0.8 m |
| Jul | 98% | 22°C | 0.9 m |
| Aug | 94% | 22°C | 1.0 m |
| Sep | 70% | 23°C | 1.2 m |
| Oct | 85% | 24°C | 1.1 m |
| Nov | 94% | 25°C | 0.9 m |
| Dec | 100% | 26°C | 0.8 m |
% = share of sampled days scoring in the favorable band, median across 3 dive sites with at least two years of history. Ringed = historical peak.
How does this compare worldwide? The Most Reliable Diving Months on Earth ranks 61 countries by the same measure.
Marine life seasons
Sighting patterns across the wider Brazil & South Atlantic region — not site-specific promises.
- Green sea turtleJuly
- Humpback whaleJun–Sep
Bars are Jan–Dec — months when sightings historically concentrate (GBIF occurrence records). Wildlife is never guaranteed.
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