Weather Trends in Rio de Janeiro, BrazilWeather Trends in Rio de Janeiro,
Brazil

Rio de Janeiro experiences a distinctly tropical climate defined by consistent warmth and high humidity throughout the year. WeatherBox data shows that the annual thermal profile features minimal seasonal fluctuation, with average daily mean temperatures only varying by 5.8°C (10.4°F) between the hotter summer and cooler winter months. During the peak summer season, the daily high averages 30.1°C (86.2°F), though the city can occasionally experience oppressive heat that reaches 33.1°C (91.6°F). Even during the coolest parts of the year, the region maintains mild winters where daily low temperatures average 18.2°C (64.8°F) and rarely fall below 16.1°C (61.0°F).

The year-round weather in this coastal environment is largely shaped by persistent atmospheric moisture and intense tropical sunlight. Average relative humidity remains elevated across all seasons, peaking at 80.5 and dropping only slightly to 76.9 during the driest period. This consistent moisture fuels distinct wet and dry cycles, contributing to an annual total precipitation of 1,198 mm (47 in). The heaviest rainfall occurs in the summer, with the wettest month averaging 168 mm (7 in), while the winter dry season sees a sharp decline to just 46 mm (2 in). Despite the regular heavy rainfall, sunlight is abundant; the sunniest month receives 270.8 of sunshine, during which time the average peak UV Index is 10.1.

Cloud coverage and coastal wind patterns provide only moderate environmental relief from the persistent warmth. Sky conditions vary significantly throughout the year, with heavy cloud cover present 85.1 of the time during the cloudiest month, compared to mostly clear skies 37.7 of the time in late winter. Wind activity is generally subdued, with the highest average monthly wind speeds reaching 12.5 km/h (7.7 mph) and peak gusts that rarely exceed 26.8 km/h (16.7 mph). Readers looking to further investigate these specific climatic averages and explore advanced weather charts can find complete datasets on the WeatherBox website.