December weather forecastBastos, Brazil

Weather in December

December, the first month of the summer in Bastos, is still a warm month, with temperature in the range of an average low of 20.7°C (69.3°F) and an average high of 29.6°C (85.3°F).

Temperature

Bastos sees the arrival of December with an average high-temperature of a moderately hot 29.6°C (85.3°F), indicating a subtle variation from November. Bastos anticipates an average minimum temperature of 20.7°C (69.3°F) in the month of December.

Heat index

For most parts of December, the heat index is calculated to be a sweltering 36°C (96.8°F). Adopt special protective actions against heat exhaustion and heat cramps. Long-duration activity risks heatstroke.
Know that the heat index computations account for shaded terrains and slight winds. Direct sunshine exposure could raise heat index values by as much as 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is a value derived by merging air temperature with the humidity to convey how the climate feels. A person's impression of weather can be shaped by many aspects, among them metabolic variations, pregnancy, and levels of physical activity. Keep it in mind, direct sunlight can augment the heat you experience, possibly pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Youngsters often neglect the necessity for rest and hydration. Thirst is a sign of advancing dehydration - thus the importance of maintaining hydration, specifically during long-lasting physical activities.
Through perspiration, the body has a natural mechanism to eliminate excessive heat via sweat evaporation. When relative humidity is on the rise, it curtails evaporation, thereby reducing the heat elimination from the body and causing the feeling of being excessively hot. Overheating and potential dehydration arise when body heat gain eclipses its release capability.

Humidity

In December, the average relative humidity is 79%.

Rainfall

In Bastos, during December, the rain falls for 25.5 days and regularly aggregates up to 160mm (6.3") of precipitation. Throughout the year, there are 193.5 rainfall days, and 1136mm (44.72") of precipitation is accumulated.

Daylight

With an average of 13h and 24min of daylight, December has the longest days of the year.
On the first day of the month, sunrise is at 05:30 and sunset at 18:53. On the last day of December, in Bastos, sunrise is at 05:42 and sunset at 19:09 -03.

Sunshine

In Bastos, the average sunshine in December is 7.7h.

UV index

January through March, July through December, with an average maximum UV index of 6, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high threat to health from exposure to the Sun's UV rays for ordinary individuals.
Note: In December, the maximum UV index of 6 translates into these guidelines:
Escape overexposure. People with light skin may incur burns in fewer than 20 minutes. The Sun's UV radiation is at its strongest between the hours of 10 a.m. and 4 p.m. Minimize direct exposure to the sun during this period. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.