December weather forecast
Grand-Santi, French Guiana

December in Grand-Santi features a significant decrease in temperature, signaling the full onset of winter. The pressure level, at 1010.7mb, inclines slightly compared to November. The predominant weather conditions signify a higher possibility of rainfall and shorter daylight hours. The UV Index decreases to 5, reflecting the daily sun exposure, which lowers due to the season. However, December stands out with its highest rainfall in the second half of the year, measuring up to 106mm (4.17"), allowing the city to bid adieu to the year on a wet note.

Temperature

Grand-Santi's average high-temperature marks a still hot 30.9°C (87.6°F) with the advent of December, closely mirroring that of the preceding month. An average low-temperature of 21.1°C (70°F) is recorded in the month of December in Grand-Santi.

Heat index

Throughout December, the heat index is calculated to be a scorching 43°C (109.4°F). Stay mindful: Heat exhaustion and heat cramps are likely. Heatstroke could follow extended physical effort.
Understand that the heat index values take into account shaded locations and mild winds. Exposure to direct sunlight may make the heat index values climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', reflects the blend of air temperature and relative humidity to give a temperature impression. 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. By being directly under the sun, it's possible for the felt temperature to increase by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Juveniles are regularly less conscious of the need to recuperate and rehydrate. Thirst is a tardy symptom of dehydration - hydration, especially during lengthy physical activities, should be maintained.
The human body has a built-in cooling mechanism through perspiration; evaporating sweat dissipates the excess heat. 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. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

The average relative humidity in December is 86%.

Rainfall

In Grand-Santi, in December, it is raining for 28.1 days, with typically 106mm (4.17") of accumulated precipitation. In Grand-Santi, French Guiana, during the entire year, the rain falls for 259.6 days and collects up to 915mm (36.02") of precipitation.

Daylight

The month with the shortest days is December, with an average of 11h and 54min of daylight.
On the first day of the month, sunrise is at 06:29 and sunset at 18:23. On the last day of December, in Grand-Santi, sunrise is at 06:44 and sunset at 18:37 -03.

Sunshine

In Grand-Santi, French Guiana, the average sunshine in December is 5.9h.

UV index

The month with the lowest UV index in Grand-Santi is December, with an average maximum UV index of 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In December, the maximum UV index of 5 suggests this advice:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.