December weather forecast
Bienvenue, French Guiana

December dishes out the wet season in full swing, with a surge in rainfall to 146mm (5.75"). As the year comes to a close, the city is lapped by increasing downpour, echoing the early days of the year. The return to high rainfall is complemented by rising humidity levels, enveloping Bienvenue in a distinctly moist climate. The sunshine hours retreat to their annual low, characteristic of a typical December, blanketing the city in a wet, warm wrap.

Temperature

As November makes way for December, Bienvenue's average high-temperature eases from a tropical 33°C (91.4°F) to a warm 29.8°C (85.6°F). Bienvenue experiences an average nighttime temperature of 22°C (71.6°F) in the month of December.

Heat index

The average heat index in December is computed to be a fiery hot 39°C (102.2°F). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
It is emphasized that the heat index's values are meant for shaded zones with mild winds. Heat index values might soar by up to 15 Fahrenheit (8 Celsius) degrees with exposure to direct sunshine.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is an indicator that blends the effects of temperature and humidity to depict perceived warmth. The effect of weather is individual, with a variety of people experiencing it differently due to distinctions in body mass, height, and level of activity. Sunshine, when direct, has the potential to intensify weather effects, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Children typically face more danger than adults as their sweat production is usually lower. Additionally, the bigger skin surface compared to their small size and the increased heat due to their activeness exacerbate the risk.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. When relative humidity is at high levels, the evaporation rate lessens, causing the body to keep more heat than it would in less humid conditions. Heat-related challenges, like dehydration, can be anticipated when body heat isn't managed effectively.

Humidity

In Bienvenue, the average relative humidity in December is 86%.

Rainfall

In Bienvenue, in December, during 25.1 rainfall days, 146mm (5.75") of precipitation is typically accumulated. In Bienvenue, during the entire year, the rain falls for 270.6 days and collects up to 1131mm (44.53") of precipitation.

Daylight

With an average of 11h and 54min of daylight, December has the shortest days of the year.
On the first day of December in Bienvenue, sunrise is at 06:21 and sunset at 18:18. On the last day of the month, sunrise is at 06:35 and sunset at 18:32 -03.

Sunshine

The average sunshine in December is 5.9h.

UV index

The months with the lowest UV index are January through July, November and December, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV radiation for the ordinary person.
Note: In December, a regular UV index of 6 translates into these guidelines:
Exercise precautions and adapt sun safety practices. Defence against skin and eye affliction is paramount. Seek shade and limit direct Sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its peak, but be aware that not all shade structures provide complete sun protection. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.