Cayenne
French Guiana
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Cayenne, French Guiana

Palm trees in a botanical garden in Cayenne, French Guiana, overlooking green fields under clear skies
Palm trees in a botanical garden in Cayenne, French Guiana, overlooking green fields under clear skies
December, the first month of the winter, in Cayenne, is still a tropical month, with average temperature fluctuating between 30.1°C (86.2°F) and 23.1°C (73.6°F).

Temperature

In December, the average high-temperature is relatively the same as in November - a still tropical 30.1°C (86.2°F). The average low-temperature, in December, is 23.1°C (73.6°F).

Rainfall

In Cayenne, it is raining for 21.6 days, with typically 340.5mm (13.4") of accumulated precipitation. In Cayenne, during the entire year, the rain falls for 221.1 days and collects up to 3516.3mm (138.4") of precipitation.

Sea temperature

In Cayenne, French Guiana, the average water temperature is 27.9°C (82.2°F).
Note: For any water activity, surface water temperatures between 25°C (77°F) and 29°C (84.2°F) are considered as excellent and extremely pleasant for lengthened periods.

Daylight

December has the shortest days of the year, with an average of 11.8h of daylight.

Sunshine

In Cayenne, French Guiana, the average sunshine in December is 4.4h.

UV index

Months with the lowest UV index in Cayenne are July and December, with an average maximum UV index of 11. A UV Index value of 11, and more, symbolizes an extreme threat to health from unsafe exposure to the UV radiation for ordinary individuals.
Note: In December, the average maximum UV index of 11 translate into the following recommendations:
Take all required precautions, as unprotected skin and eyes can burn in minutes. 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. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. A broad-spectrum sunscreen of SPF 30+ should be liberally applied and re-applied every two hours, and immediately after an outdoor workout or a swim. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.

What is the temperature in December in Cayenne?

In Cayenne, in December, the average high-temperature is 30.1°C (86.2°F), and the average low-temperature is 23.1°C (73.6°F).

How much does it rain in Cayenne in December?

In Cayenne, in December, during 21.6 rainfall days, 340.5mm (13.4") of precipitation is typically accumulated.

What is the water temperature in December in Cayenne?

In Cayenne, French Guiana, in December, the average water temperature is 27.9°C (82.2°F). For any water activity, surface water temperatures between 25°C (77°F) and 29°C (84.2°F) are considered as excellent and extremely pleasant for lengthened periods.

What is the month with the shortest days in Cayenne?

December has the shortest days of the year in Cayenne, with an average of 11.8h of daylight.

How many hours of daylight does Cayenne have in December?

In December, the average length of the day in Cayenne is 11.8h.

How many hours of sunshine does Cayenne have in December?

In Cayenne, French Guiana, the average sunshine in December is 4.4h.

What are the months with the lowest UV index in Cayenne?

July and December, with an average maximum UV index of 11, are months with the lowest UV index in Cayenne.

What is the UV index intensity in December in Cayenne?

In December, the average daily maximum UV index in Cayenne, French Guiana, is 11. A UV Index value of 11, and more, symbolizes an ultimate hazard to health from the exposure to the Sun's UV rays.
Average temperature in December - Cayenne, French Guiana
  • Average high temperature in December: 30.1°C

The warmest month (with the highest average high temperature) is October (32.2°C).
The month with the lowest average high temperature is January (29.1°C).

  • Average low temperature in December: 23.1°C

The month with the highest average low temperature is April (23.7°C).
The coldest month (with the lowest average low temperature) is September (22.2°C).

Average rainfall in December - Cayenne, French Guiana
  • Average rainfall in December: 340.5mm

The wettest month (with the highest rainfall) is May (579.4mm).
The driest month (with the lowest rainfall) is September (55.7mm).

Average rainfall days in December - Cayenne, French Guiana
  • Average rainfall days in December: 21.6 days

The month with the highest number of rainy days is May (26.4 days).
The month with the lowest number of rainy days is September (7.1 days).

Average sea temperature in December - Cayenne, French Guiana
  • Average sea temperature in December: 27.9°C

The best month for swimming (with the highest average sea temperature) is August (28.7°C).
The coldest month (with the lowest average sea temperature) is February (27.3°C).

Average daylight in December / Average sunshine in December - Cayenne, French Guiana
  • Average daylight in December: 11.8h

Months with the longest days are June and July (Average daylight: 12.4h).
The month with shortest days is December (Average daylight: 11.8h).

  • Average sunshine in December: 4.4h

The month with most sunshine is September (Average sunshine: 8.5h).
The month with least sunshine is January (Average sunshine: 3h).

Average UV index in December - Cayenne, French Guiana
  • Average UV index in December: 11

Months with the highest UV index are January, February, March, April, May, June, August, September, October and November (UV index 12).
Months with the lowest UV index are July and December (UV index 11).