Last updated: June 24, 2025
In December, the average temperature in Rio, United States hovers around -2°C (28°F). Expect a chilling minimum of -23°C (-8°F), while the warmest days can reach up to 18°C (65°F). Additionally, precipitation averages 46 mm (1.8 in) over 6 days, contributing to an average humidity of 81%. Stay prepared for a mix of frosty and mild conditions!
In December in Rio, the average temperature is -2°C (28°F). The maximum can reach 18°C (65°F) and the minimum can be as low as -23°C (-8°F). Travelers should be prepared for a wide range of temperatures when visiting during this time.
In Rio in December, the precipitation amount is 46 mm (1.8 in) over a span of 6 days.
In Rio in December, humidity is 81%. With an average temperature of -2°C (28°F), this humidity feels like a biting chill that seeps into your bones, making travel uncomfortable and necessitating extra layers to stay warm and dry.
In Rio in December, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Rio, you can visit Hourly UV Index in Rio.
UV Risk Categories
Weather in Rio varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Rio, focusing on differences in temperature, rainfall, humidity, and UV levels.
Temperature | Precipitation | Humidity | UV | |
---|---|---|---|---|
January Weather | -6°C (21°F) | 47 mm (1.9 inches) | 85% | moderate |
February Weather | -6°C (21°F) | 52 mm (2.0 inches) | 85% | moderate |
March Weather | 2°C (35°F) | 58 mm (2.3 inches) | 85% | moderate |
April Weather | 7°C (45°F) | 98 mm (3.9 inches) | 85% | very high |
May Weather | 15°C (59°F) | 127 mm (5.0 inches) | 78% | very high |
June Weather | 21°C (70°F) | 112 mm (4.4 inches) | 80% | very high |
July Weather | 23°C (74°F) | 103 mm (4.1 inches) | 78% | very high |
August Weather | 22°C (71°F) | 100 mm (3.9 inches) | 76% | very high |
September Weather | 18°C (65°F) | 98 mm (3.8 inches) | 79% | high |
October Weather | 10°C (51°F) | 113 mm (4.5 inches) | 83% | moderate |
November Weather | 2°C (36°F) | 44 mm (1.7 inches) | 88% | moderate |
December Weather | -2°C (28°F) | 46 mm (1.8 inches) | 81% | low |