December weather forecast
São Fernando, Brazil

December, the first month of the summer in São Fernando, is still a hot month, with temperature in the range of an average high of 34.9°C (94.8°F) and an average low of 24.4°C (75.9°F).

Temperature

São Fernando's weather in December, with an average high-temperature of a tropical 34.9°C (94.8°F), subtly shifts from November's 35.5°C (95.9°F). An average low-temperature of 24.4°C (75.9°F) is noted during the month of December.

Heat index

During December, the heat index is calculated to be a blistering 41°C (105.8°F). Undertake additional safety actions, risk of heat cramps and heat exhaustion is significant. Persistent activity may induce heatstroke.
Keep in mind the heat index values are meant for areas in shade and with light wind. If directly exposed to the sun, the heat index could rise by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is an aggregate value of air's warmth and moisture to show the human-felt temperature. Factors such as metabolic variation, pregnancy, and physical activity play a role in one's impression of weather. 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. Young ones are generally more prone to risk than adults due to their reduced ability to sweat. Their large skin surface area relative to their diminutive bodies and elevated heat production from their activities further enhance this risk.
The natural cooling mechanism in humans involves perspiration, where the evaporation of sweat balances out excessive warmth. Elevated relative humidity diminishes evaporation, thereby reducing the body's ability to shed heat and creating a feeling of being too warm. Heat absorption that surpasses the body's shedding capability can lead to overheating and varying levels of dehydration.

Humidity

The average relative humidity in December is 52%.

Rainfall

In São Fernando, in December, it is raining for 7.2 days, with typically 15mm (0.59") of accumulated precipitation. In São Fernando, during the entire year, the rain falls for 122.6 days and collects up to 442mm (17.4") of precipitation.

Daylight

The month with the longest days in São Fernando is December, with an average of 12h and 30min of daylight.
On the first day of the month, sunrise is at 05:03 and sunset at 17:32. On the last day of December, sunrise is at 05:17 and sunset at 17:46 -03.

Sunshine

In São Fernando, the average sunshine in December is 9.2h.

UV index

The months with the highest UV index are January through December, with an average maximum UV index of 7. January through December, with an average maximum UV index of 7, are months with the lowest UV index in São Fernando. A UV Index of 6 to 7 symbolizes a high health vulnerability from unprotected exposure to Sun's UV rays for the average person.
Note: A maximum UV index of 7 in December translates into the following recommendations:
Resist overexposure. Safeguarding from solar damage is indispensable. 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. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.