December weather forecast
Barthélemy, French Guiana

December marks the end of the transitional phase with rainfall rising to 204mm (8.03"), placing it amongst the months with the heaviest downpours. Barthélemy in December stays true to its tropical climate with relatively high temperatures and high humidity. Notwithstanding the high precipitation, daylight hours hold steady at 11.9, the same as in January. Wind speed escalates, accompanying the increase in rainfall and providing a comforting coolness. Consequently, December's weather in Barthélemy concludes the year staying consistent with the prevalent tropical climate, showcasing high rainfall and maintaining the temperature and humidity ranges.

Temperature

December in Barthélemy registers an average high-temperature of a warm 28.8°C (83.8°F), slightly varied from November's 30.8°C (87.4°F). Throughout December, Barthélemy records a steady low-temperature average of 24.5°C (76.1°F), a minor decrease from its daytime counterpart.

Heat index

For most parts of December, the heat index is evaluated at a fiery hot 35°C (95°F). Ensure additional precautions, heat exhaustion and heat cramps may be expected. Heatstroke could occur from sustained activity.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Uninterrupted exposure to the sun may boost the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', arises from combining readings of air temperature and relative moisture content. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. One should be aware that direct sunshine can amplify the perceived temperature, raising the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Children regularly disregard the necessity to rest and replenish fluids. Thirst is a late symptom of dehydration - thus, maintaining hydration, particularly during long-lasting physical activities, is essential.
The body's self-cooling mechanism is rooted in perspiration, where evaporating sweat cools down excessive warmth. When the level of relative humidity is elevated, evaporation diminishes, causing more warmth to be retained in the body than in dry air. Increasing body temperatures can be a precursor to dehydration if the body can't shed the extra heat.

Humidity

In Barthélemy, the average relative humidity in December is 83%.

Rainfall

In Barthélemy, in December, it is raining for 25.2 days, with typically 204mm (8.03") of accumulated precipitation. In Barthélemy, during the entire year, the rain falls for 277 days and collects up to 1707mm (67.2") of precipitation.

Daylight

December has the shortest days of the year, with an average of 11h and 54min of daylight.
On the first day of the month, sunrise is at 06:22 and sunset at 18:16. On the last day of December, in Barthélemy, sunrise is at 06:36 and sunset at 18:29 -03.

Sunshine

The average sunshine in December is 7.3h.

UV index

The months with the lowest UV index are January through May and December, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV radiation for the ordinary person.
Note: A maximum high daily UV index of 6 during December translates into the following directions:
Adhere to precautions and respect sun safety doctrines. Avoiding sunburn is vital. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.