December weather forecast
Boa Vista, Brazil

Closing out the year, December brings a warm, moderate climate to Boa Vista. The temperature reaches up to 33.2°C (91.8°F) which makes for a warm end of the year. An increase in wind speed back to 11.1km/h (6.9mph) signifies a return to normal climatic conditions. With rainfall at a mere 42mm (1.65"), the weather stays predominantly dry. All in all, December offers a comfortable mix of warmth and moderate rainfall for the city.

Temperature

Boa Vista commences December with an average high-temperature of a still tropical 33.2°C (91.8°F), maintaining a close resemblance to the previous month. Boa Vista's nights in December cool down to an average low-temperature of 24.4°C (75.9°F).

Heat index

The average heat index in December is appraised at a blistering 42°C (107.6°F). Undertake additional safety actions, risk of heat cramps and heat exhaustion is significant. Persistent activity may induce heatstroke.
Remember that heat index calculations are made for conditions in the shade with light wind. A rise in the heat index by 15 Fahrenheit (8 Celsius) degrees may result from direct sunlight exposure.
Note: The heat index, also known as 'felt air temperature' or 'real feel', is a single figure representing how weather conditions feel when combining temperature and humidity. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. Realize that direct exposure to sunlight can augment the felt heat, leading to a potential increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Children often overlook the need for breaks and fluid intake. Thirst is a late-stage sign of dehydration - hence, it is necessary to stay hydrated, especially during extended periods of physical activities.
One way the human body deals with excessive warmth is by perspiring and allowing sweat to evaporate. Increased relative humidity interferes with body cooling by slowing the rate of evaporation, resulting in a slower body cooling rate and a heightened feeling of heat. When heat uptake goes beyond the body's cooling mechanisms, there's a surge in body temperature, posing health risks.

Humidity

In December, the average relative humidity in Boa Vista is 65%.

Rainfall

In Boa Vista, during December, the rain falls for 14.9 days and regularly aggregates up to 42mm (1.65") of precipitation. Throughout the year, there are 241.8 rainfall days, and 1216mm (47.87") of precipitation is accumulated.

Daylight

With an average of 12h and 0min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 05:52 and sunset at 17:51. On the last day of December, sunrise is at 06:07 and sunset at 18:04 -04.

Sunshine

In December, the average sunshine is 8h.

UV index

The months with the highest UV index are January through May, July through December, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV radiation for the average person.
Note: In December, the maximum UV index of 7 translates into these guidelines:
Escape overexposure. People with light skin may incur burns in fewer than 20 minutes. Limit your direct sun exposure, especially between 10 a.m. and 4 p.m., when UV radiation is strongest. Shade structures might not provide complete sun protection. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.