a precious asset for surfers in the region is surfline, a website publishing constantly updated reports and swell forecasts for rio de janeiro southern shore - published by surfline, this clickable map shows the height of the waves on a number of beaches in both rio de janeiro and niterói. 

this chart shows the forecast for all waves in rio's southern region - a summary forecast for a variety of beaches and surf spots in rio de janeiro can be seen on this page.

this page, published and updated daily by the brazilian navy, shows the overall daily forecast for rio de janeiro state's coast, including waves (ondas), visibility (visibilidade), and maximum and minimum temperatures along the coast (temperatura).