December weather forecast
Altamira, Brazil

The first month of the summer, December, is also a hot month in Altamira, Brazil, with an average temperature varying between 32.4°C (90.3°F) and 22.7°C (72.9°F).

Temperature

The arrival of December is marked by an average high-temperature of a still hot 32.4°C (90.3°F), bearing a close resemblance to November. Throughout the month of December, the nighttime temperature dips to an average of 22.7°C (72.9°F).

Heat index

December's average heat index is evaluated at a burning hot 45°C (113°F). Take caution: Heat exhaustion and heat cramps are probable. Heatstroke may be imminent with ongoing effort.
Always consider that heat index estimations are for light winds and places in the shade. Direct sunlight might cause an increase of up to 15 Fahrenheit (8 Celsius) degrees in the heat index.
Note: The heat index, also known as 'real feel' or 'feels like', is a numerical representation of warmth when taking temperature and moisture levels into account. The impact of weather on an individual can be subjective, affected by the person's activity and heat perception, which can vary due to elements including wind, clothing, and metabolic differences. It is essential to realize that direct sunlight can escalate the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Youngsters generally face more threats than adults given their lesser ability to sweat. Coupled with their larger skin surface relative to their small bodies and higher heat production due to their activities, they are more endangered.
One way the human body deals with excessive warmth is by perspiring and allowing sweat to evaporate. An upsurge in relative humidity affects normal body cooling mechanisms by slowing evaporation, hence reducing the rate at which the body cools and intensifying the perception of heat. Accumulating more heat than the body can dissipate leads to an uptick in body temperature, with potential heat stress consequences.

Humidity

In December, the average relative humidity in Altamira, Brazil, is 79%.

Rainfall

In Altamira, in December, it is raining for 24.5 days, with typically 139mm (5.47") of accumulated precipitation. Throughout the year, there are 260.4 rainfall days, and 1317mm (51.85") of precipitation is accumulated.

Daylight

The month with the longest days in Altamira is December, with an average of 12h and 18min of daylight.
On the first day of the month, sunrise is at 06:09 and sunset at 18:26. On the last day of December, sunrise is at 06:22 and sunset at 18:41 -03.

Sunshine

In Altamira, the average sunshine in December is 7.1h.

UV index

The months with the highest UV index are June through December, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In December, a regular UV index of 7 translates into these guidelines:
Deflect overexposure. Sun protection is a necessity. Between 10 a.m. and 4 p.m., the Sun emits the most powerful UV radiation. Limit direct exposure to the Sun during these hours. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.