December weather forecast
Nantes, Brazil

The first month of the summer, December, is also a hot month in Nantes, Brazil, with an average temperature varying between 30°C (86°F) and 21.3°C (70.3°F).

Temperature

Nantes measures an average high-temperature of a still hot 30°C (86°F) in December, nearly consistent with the preceding month. In December, the temperature drops to an average of 21.3°C (70.3°F) at night.

Heat index

December's mean heat index is appraised at a fiery hot 37°C (98.6°F). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
From a standpoint of the heat index, values pertain to shaded conditions and mild breezes. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', is a measure of how hot it feels when the actual air humidity is factored in. Factors encompassing physical activity, clothing, and metabolic differences have a role in shaping the individual's impression of temperature. Be mindful that being in direct sunlight might mean feeling hotter, with the heat index rising by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.
The innate cooling system of the human body revolves around perspiration, with the evaporation of sweat being central to this process. Elevated relative humidity diminishes evaporation, thereby reducing the body's ability to shed heat and creating a feeling of being too warm. Accumulating heat beyond the body's cooling measures leads to rising temperatures and potential ailments.

Humidity

The average relative humidity in December is 78%.

Rainfall

In Nantes, in December, during 25.8 rainfall days, 168mm (6.61") of precipitation is typically accumulated. In Nantes, during the entire year, the rain falls for 196.8 days and collects up to 1260mm (49.61") of precipitation.

Daylight

December has the longest days of the year, with an average of 13h and 30min of daylight.
On the first day of December, sunrise is at 05:31 and sunset at 18:56. On the last day of the month, sunrise is at 05:43 and sunset at 19:13 -03.

Sunshine

In Nantes, the average sunshine in December is 7.8h.

UV index

January through March, June through December, with an average maximum UV index of 6, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for the average person.
Note: The maximum daily UV index of 6 in December converts into the following recommendations:
Implement precautions and maintain sun safety methods. Avoidance of sunburn is demanded. From 10 a.m. to 4 p.m., when UV radiation is at its strongest, limit direct exposure to the Sun and note that shade structures may not provide full sun protection. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.