Climate - Cayenne (French Guiana)

The climate of Cayenne is tropical, hot and humid throughout the year, with a relatively dry, slightly warmer season from July to November and a rainy season from December to June, during which the rains are very abundant, at monsoon level. Sometimes, in February or March, there can be a period of fairly good weather for one or two weeks, "the short summer of March".
The city is the capital of French Guiana and is located in the central part of the coast, at almost 5 degrees north latitude, between the mouths of the rivers Cayenne to the north and Mahury to the south, where the port of Dégrad des Cannes is located.
Off the city are some small islands, although the more famous Devil's Island is further north, off the city of Kourou.
Since the dry season is short and not very pronounced, the area around the city, and French Guiana in general, is covered by rainforest. However, the driest months are September and October.
From January to April, the north-east trade winds blow at a moderate intensity, while from June to August, the wind is weaker.

The average temperature of the coldest months (January, February) is of 26.4 °C (79.5 °F), that of the warmest months (September, October) is of 27.4 °C (81.4 °F). Here are the average temperatures.
Precipitation amounts to 3350 millimeters (131.9 inches) per year: it is therefore very abundant. It ranges from 55 mm (2.2 in) in the driest month (October) to 580 mm (22.8 in) in the wettest one (May). Here is the average precipitation.
The sea temperature ranges from 27 °C (27 °F) in January, February to 28.5 °C (28.5 °F) in June, July, August, September. Here are the average sea temperatures.
On average, there are around 2005 sunshine hours per year. Here are the average sunshine hours per day.

Cayenne - Weather by month

Based on the period 1991-2020
(January - February - March - April - May - June - July - August - September - October - November - December)

In January, the coldest month of the year, the average temperature is of 26.4 °C (80 °F), with a minimum of 23.4 °C (74.1 °F) and a maximum of 29.4 °C (84.9 °F).
On the coldest nights of the month, the temperature usually drops to around 21 °C (70 °F). However, in January 2014, it dropped to 18.6 °C (65.5 °F).
On the warmest days of the month, the temperature usually reaches around 31 °C (87.5 °F). However, in January 2005, it reached 32.5 °C (90.5 °F).
Precipitation amounts to 350 mm (13.8 in), distributed over 25 days.
On average, there are 95 hours of sunshine per month, i.e. 3 hours per day.
The average humidity is 85%.
The average wind speed is 10 kph (6 kph).
The average sea temperature is of 27 °C (81 °F).

In February, the coldest month of the year, the average temperature is of 26.4 °C (80 °F), with a minimum of 23.5 °C (74.3 °F) and a maximum of 29.3 °C (84.7 °F).
On the coldest nights of the month, the temperature usually drops to around 21 °C (70 °F). However, in February 2016, it dropped to 19.7 °C (67.5 °F).
On the warmest days of the month, the temperature usually reaches around 31 °C (87.5 °F). However, in February 1998, it reached 32.3 °C (90.1 °F).
Precipitation amounts to 330 mm (13 in), distributed over 22 days.
On average, there are 90 hours of sunshine per month, i.e. 3.5 hours per day.
The average humidity is 84%.
The average wind speed is 12 kph (7 kph).
The average sea temperature is of 27 °C (81 °F).

In March, the average temperature is of 26.8 °C (80 °F), with a minimum of 23.7 °C (74.7 °F) and a maximum of 29.8 °C (85.6 °F).
On the coldest nights of the month, the temperature usually drops to around 21.5 °C (70.5 °F). However, in March 2017, it dropped to 19.5 °C (67.1 °F).
On the warmest days of the month, the temperature usually reaches around 31 °C (88 °F). However, in March 2010, it reached 32.2 °C (90 °F).
Precipitation amounts to 290 mm (11.4 in), distributed over 22 days.
On average, there are 120 hours of sunshine per month, i.e. 4 hours per day.
The average humidity is 83%.
The average wind speed is 12 kph (7 kph).
The average sea temperature is of 27.5 °C (81.5 °F).

In April, the average temperature is of 26.9 °C (80 °F), with a minimum of 23.8 °C (74.8 °F) and a maximum of 30 °C (86 °F).
On the coldest nights of the month, the temperature usually drops to around 22 °C (71.5 °F). However, in April 2018, it dropped to 20.7 °C (69.3 °F).
On the warmest days of the month, the temperature usually reaches around 31.5 °C (89 °F). However, in April 2010, it reached 33 °C (91.4 °F).
Precipitation amounts to 415 mm (16.3 in), distributed over 23 days.
On average, there are 125 hours of sunshine per month, i.e. 4 hours per day.
The average humidity is 85%.
The average wind speed is 10 kph (6 kph).
The average sea temperature is of 27.5 °C (82 °F).

In May, the average temperature is of 26.8 °C (80 °F), with a minimum of 23.6 °C (74.5 °F) and a maximum of 30.1 °C (86.2 °F).
On the coldest nights of the month, the temperature usually drops to around 22 °C (71.5 °F). However, in May 2016, it dropped to 20.2 °C (68.4 °F).
On the warmest days of the month, the temperature usually reaches around 32 °C (89.5 °F). However, in May 2010, it reached 33.7 °C (92.7 °F).
Precipitation amounts to 580 mm (22.8 in), distributed over 27 days.
On average, there are 120 hours of sunshine per month, i.e. 4 hours per day.
The average humidity is 87%.
The average wind speed is 8 kph (5 kph).
The average sea temperature is of 28 °C (82.5 °F).

In June, the average temperature is of 26.8 °C (80 °F), with a minimum of 23 °C (73.4 °F) and a maximum of 30.5 °C (86.9 °F).
On the coldest nights of the month, the temperature usually drops to around 21.5 °C (71 °F). However, in June 2014, it dropped to 20.7 °C (69.3 °F).
On the warmest days of the month, the temperature usually reaches around 32.5 °C (90 °F). However, in June 2010, it reached 33.7 °C (92.7 °F).
Precipitation amounts to 395 mm (15.6 in), distributed over 25 days.
On average, there are 150 hours of sunshine per month, i.e. 5 hours per day.
The average humidity is 87%.
The average wind speed is 6 kph (4 kph).
The average sea temperature is of 28.5 °C (83 °F).

In July, the average temperature is of 26.8 °C (80 °F), with a minimum of 22.5 °C (72.5 °F) and a maximum of 31.1 °C (88 °F).
On the coldest nights of the month, the temperature usually drops to around 21.5 °C (70.5 °F). However, in July 2014, it dropped to 20.2 °C (68.4 °F).
On the warmest days of the month, the temperature usually reaches around 33 °C (91 °F). However, in July 2010, it reached 33.9 °C (93 °F).
Precipitation amounts to 265 mm (10.4 in), distributed over 21 days.
On average, there are 200 hours of sunshine per month, i.e. 6.5 hours per day.
The average humidity is 86%.
The average wind speed is 6 kph (4 kph).
The average sea temperature is of 28.5 °C (83 °F).

In August, the average temperature is of 27.2 °C (81 °F), with a minimum of 22.5 °C (72.5 °F) and a maximum of 31.8 °C (89.2 °F).
On the coldest nights of the month, the temperature usually drops to around 21 °C (70 °F). However, in August 2014, it dropped to 20 °C (68 °F).
On the warmest days of the month, the temperature usually reaches around 33.5 °C (92 °F). However, in August 1998, it reached 34.2 °C (93.6 °F).
Precipitation amounts to 135 mm (5.3 in), distributed over 14 days.
On average, there are 235 hours of sunshine per month, i.e. 7.5 hours per day.
The average humidity is 83%.
The average wind speed is 7 kph (4 kph).
The average sea temperature is of 28.5 °C (83 °F).

In September, the warmest month of the year, the average temperature is of 27.4 °C (81 °F), with a minimum of 22.5 °C (72.5 °F) and a maximum of 32.4 °C (90.3 °F).
On the coldest nights of the month, the temperature usually drops to around 21 °C (70 °F). However, in September 2016, it dropped to 19.5 °C (67.1 °F).
On the warmest days of the month, the temperature usually reaches around 33.5 °C (92.5 °F). However, in September 2017, it reached 35.2 °C (95.4 °F).
Precipitation amounts to 60 mm (2.4 in), distributed over 7 days.
On average, there are 255 hours of sunshine per month, i.e. 8.5 hours per day.
The average humidity is 80%.
The average wind speed is 8 kph (5 kph).
The average sea temperature is of 28.5 °C (83 °F).

In October, the warmest month of the year, the average temperature is of 27.4 °C (81 °F), with a minimum of 22.4 °C (72.3 °F) and a maximum of 32.5 °C (90.5 °F).
On the coldest nights of the month, the temperature usually drops to around 21 °C (69.5 °F). However, in October 1998, it dropped to 19.9 °C (67.8 °F).
On the warmest days of the month, the temperature usually reaches around 34 °C (93 °F). However, in October 1999, it reached 35.1 °C (95.2 °F).
Precipitation amounts to 55 mm (2.2 in), distributed over 7 days.
On average, there are 255 hours of sunshine per month, i.e. 8.5 hours per day.
The average humidity is 80%.
The average wind speed is 8 kph (5 kph).
The average sea temperature is of 28 °C (83 °F).

In November, the average temperature is of 27.2 °C (81 °F), with a minimum of 22.7 °C (72.9 °F) and a maximum of 31.7 °C (89.1 °F).
On the coldest nights of the month, the temperature usually drops to around 21 °C (69.5 °F). However, in November 2018, it dropped to 19.4 °C (66.9 °F).
On the warmest days of the month, the temperature usually reaches around 33 °C (91.5 °F). However, in November 2008, it reached 34.2 °C (93.6 °F).
Precipitation amounts to 140 mm (5.5 in), distributed over 13 days.
On average, there are 210 hours of sunshine per month, i.e. 7 hours per day.
The average humidity is 82%.
The average wind speed is 8 kph (5 kph).
The average sea temperature is of 28 °C (82.5 °F).

In December, the average temperature is of 26.7 °C (80 °F), with a minimum of 23.1 °C (73.6 °F) and a maximum of 30.3 °C (86.5 °F).
On the coldest nights of the month, the temperature usually drops to around 21 °C (70 °F). However, in December 2012, it dropped to 19.4 °C (66.9 °F).
On the warmest days of the month, the temperature usually reaches around 32 °C (89.5 °F). However, in December 2004, it reached 34.1 °C (93.4 °F).
Precipitation amounts to 335 mm (13.2 in), distributed over 23 days.
On average, there are 145 hours of sunshine per month, i.e. 4.5 hours per day.
The average humidity is 85%.
The average wind speed is 9 kph (6 kph).
The average sea temperature is of 27.5 °C (81.5 °F).