December weather forecast
Rio de Janeiro, Brazil

Christ the Redeemer statue atop Mount Corcovado, overlooking the seaside city of Rio de Janeiro, Brazil
Christ the Redeemer statue atop Mount Corcovado, overlooking the seaside city of Rio de Janeiro, Brazil

Weather in December

The first month of the summer, December, is also a moderately hot month in Rio de Janeiro, Brazil, with an average temperature fluctuating between 23°C (73.4°F) and 28.2°C (82.8°F).

Temperature

In December, the average high-temperature is relatively the same as in November - a still warm 28.2°C (82.8°F). In December, the average low-temperature is 23°C (73.4°F).

Heat index

In December, the average heat index is computed to be a hot 32.8°C (91°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Note that heat index values are valued for light wind and location in the shade. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'apparent temperature', 'felt air temperature', or 'feels like', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. Additional factors like pregnancy, metabolic differences, differences in body mass, height, and shape, and activity influence one's weather impression. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.

Humidity

The average relative humidity in December in Rio de Janeiro is 81%.

Rainfall

In Rio de Janeiro, during December, the rain falls for 21.9 days and regularly aggregates up to 98mm (3.86") of precipitation. Throughout the year, in Rio de Janeiro, there are 192.5 rainfall days, and 812mm (31.97") of precipitation is accumulated.

Sea temperature

In Rio de Janeiro, the average water temperature is 24°C (75.2°F).
Note: Depending on a person's sensitivity to cold, with regards to sunshine, wind, and air temperature, a quick swim in 24°C (75.2°F) water may be enjoyable. (FYI: The official water temperature required for the Olympic swimming competition is 25°C (77°F) to 28°C (82.4°F).)

Daylight

December has the longest days of the year in Rio de Janeiro, with an average of 13h and 31min of daylight.
On the first day of the month, sunrise is at 04:58 and sunset at 18:24. On the last day of December, sunrise is at 05:10 and sunset at 18:41 -03.

Sunshine

The average sunshine in December is 8.3h.

UV index

In Rio de Janeiro, the average daily maximum UV index in December is 6. A UV Index reading of 6 to 7 represents a high health hazard from unsafe exposure to UV radiation for the average person.
Note: The average daily UV index of 6 in December transform into the following instructions:
Take precautions and utilize sun safety practices. Protection against skin and eye damage is required. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.
[Resources]

FAQ

What is the temperature in December in Rio de Janeiro?

The average high-temperature, in December, in Rio de Janeiro, Brazil, is 28.2°C (82.8°F), while the average low-temperature is 23°C (73.4°F). The average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines relative humidity and air temperature, in December is computed to be 32.8°C (91°F).

What is the average humidity in December in Rio de Janeiro?

The average relative humidity in December is 81%.

How many days does it rain in December in Rio de Janeiro?

In December, in Rio de Janeiro, Brazil, the rain falls for 21.9 days. Throughout December, 98mm (3.86") of precipitation is accumulated.

What is the sea temperature in December in Rio de Janeiro?

In December, the average sea temperature in Rio de Janeiro, Brazil, is 24°C (75.2°F). For individuals prone to feeling cold, swimming in 23°C (73.4°F) is still regarded as intolerable. A wetsuit is not a necessity, but sunshine, wind, and air temperature are essential factors for relishing swimming at 24°C (75.2°F).

When are the longest days in Rio de Janeiro?

The month with the longest days is December, with an average of 13h and 31min of daylight.

How many hours of daylight does Rio de Janeiro have in December?

In Rio de Janeiro, the average day length in December is 13h and 31min.

What time are sunrise and sunset in December in Rio de Janeiro?

On the first day of December in Rio de Janeiro, sunrise is at 04:58 and sunset at 18:24. On the last day of the month, sunrise is at 05:10 and sunset at 18:41 -03.

How many hours of sunshine does Rio de Janeiro have in December?

In Rio de Janeiro, the average sunshine duration in December is 8.3h.

How high is the UV index in December in Rio de Janeiro?

The average daily maximum UV index in December in Rio de Janeiro, Brazil, is 6. A UV Index value of 6 to 7 symbolizes a high health risk from unsafe exposure to Sun's UV rays.

Average temperature in December
Rio de Janeiro, Brazil

Average temperature in December - Rio de Janeiro, Brazil
  • Average high temperature in December: 28.2°C

The warmest month (with the highest average high temperature) is February (29.7°C).
The month with the lowest average high temperature is July (24°C).

  • Average low temperature in December: 23°C

The month with the highest average low temperature is January (23.7°C).
The coldest month (with the lowest average low temperature) is August (18.5°C).

[Resources]

Average pressure in December
Rio de Janeiro, Brazil

Average pressure in December - Rio de Janeiro, Brazil
  • Average pressure in December: 1011.9mbar

The month with the highest atmospheric pressure is July (1020.5mbar).
The month with the lowest atmospheric pressure is December (1011.9mbar).

[Resources]

Average wind speed in December
Rio de Janeiro, Brazil

Average wind speed in December - Rio de Janeiro, Brazil
  • Average wind speed in December: 9.5km/h

The windiest months (with the highest average wind speed) are August and September (11.3km/h).
The calmest month (with the lowest average wind speed) is March (8.7km/h).

[Resources]

Average humidity in December
Rio de Janeiro, Brazil

Average humidity in December - Rio de Janeiro, Brazil
  • Average humidity in December: 81%

The month with the highest relative humidity is November (82%).
The month with the lowest relative humidity is August (76%).

[Resources]

Average rainfall in December
Rio de Janeiro, Brazil

Average rainfall in December - Rio de Janeiro, Brazil
  • Average rainfall in December: 98mm

The wettest month (with the highest rainfall) is November (119mm).
The driest month (with the least rainfall) is June (29mm).

[Resources]

Average rainfall days in December
Rio de Janeiro, Brazil

Average rainfall days in December - Rio de Janeiro, Brazil
  • Average rainfall days in December: 21.9 days

The month with the highest number of rainy days is March (22.7 days).
The month with the least rainy days is July (9.3 days).

[Resources]

Average sea temperature in December
Rio de Janeiro, Brazil

Average sea temperature in December - Rio de Janeiro, Brazil
  • Average sea temperature in December: 24°C

The best month for swimming (with the highest average sea temperature) is March (25.8°C).
The coldest month (with the lowest average sea temperature) is September (21.6°C).

[Resources]

Average daylight in December /
Average sunshine in December
Rio de Janeiro, Brazil

Average daylight in December / Average sunshine in December - Rio de Janeiro, Brazil
  • Average daylight in December: 13h and 31min

The month with the longest days is December (Average daylight: 13h and 31min).
The month with the shortest days is June (Average daylight: 10h and 45min).

  • Average sunshine in December: 8.3h

The month with the most sunshine is February (Average sunshine: 8.8h).
The month with the least sunshine is October (Average sunshine: 7.5h).

[Resources]

Average sunshine days in December
Rio de Janeiro, Brazil

Average sunshine days in December - Rio de Janeiro, Brazil
  • Average sunshine days in December: 4.8 days

The month with the most sunshine days is July (20.6 days).
The month with the least sunshine days is December (4.8 days).

[Resources]

Average UV index in December
Rio de Janeiro, Brazil

Average UV index in December - Rio de Janeiro, Brazil
  • Average UV index in December: 6

The month with the highest UV index is January (UV index 7).
The month with the lowest UV index is September (UV index 5).

[Resources]

Average cloud cover in December
Rio de Janeiro, Brazil

Average cloud cover in December - Rio de Janeiro, Brazil
  • Average cloud cover in December: 39

The month with the most cloud cover is November (Cloud cover 46).
The month with the least cloud cover is February (Cloud cover 28).

[Resources]

Average visibility in December
Rio de Janeiro, Brazil

Average visibility in December - Rio de Janeiro, Brazil
  • Average visibility in December: 9km

The months with the highest visibility are February, May, June, July, August and September (10km).
The months with the lowest visibility are January, March, April, October, November and December (9km).

[Resources]

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location
* you will be automatically redirected to the weather forecast for your location