Climate and monthly weather forecast
French Guiana

French Guiana, located on the northeast coast of South America, is characterised by its extensive tropical rainforests and low-lying coastal plains. With the Atlantic Ocean to its east and dense, undulating jungle to its west, the country experiences a uniformly tropical climate throughout the year. This warm, humid weather is influenced by its proximity to the Equator, which allows for minimal variation in temperature.

Designated as a tropical rainforest climate under the Köppen system (denoted 'Af'), French Guiana receives substantial rainfall throughout the year. Average temperatures hover around a warm 27°C (80.6°F), rarely deviating more than a few degrees in either direction. Rainfall is abundant, with annual precipitation reaching up to 3,0mm (0") in the coastal areas and even more in the interior rainforest regions. This consistent precipitation leads to a high relative humidity, typically around 80%.

While the climate in French Guiana remains warm and humid throughout the year, the best time to visit would arguably be from July to December. This period, often referred to as the "lesser rainy season", sees slightly reduced rainfall compared to other parts of the year. This may afford visitors more opportunities for outdoor activities such as trekking in the rainforest or exploring the diverse wildlife. However, it's important to note that even during this period, downpours are not uncommon and weather can be unpredictable.

The "greater rainy season", which lasts from January to June, can pose challenges for travelers due to increased precipitation. Especially from April to June, rainfall intensifies and can result in localized flooding. As many roads in French Guiana are unpaved, transport can become challenging. Moreover, the abundant rainfall can limit outdoor activities, as heavy showers may occur without warning. Consequently, this period may not be the most comfortable or convenient for travel.

It is important to remember that French Guiana, being located in the tropics, does not experience a traditional spring season as understood in temperate regions. However, for the sake of comparison, the March-May period in French Guiana falls within the heavy rainy season. Temperatures during these months range from 23°C (73.4°F) to 31°C (87.8°F). Rainfall is plentiful, with monthly totals often exceeding 300mm (11.81"). The skies are frequently overcast, and high humidity is the norm.

June through August, correlating with the traditional summer months in the Northern Hemisphere, marks the start of the lesser rainy season in French Guiana. While still prone to regular rainfall, this period tends to be drier than the previous months. Temperatures continue to range from a comfortable 23°C (73.4°F) at night to a warmer 31°C (87.8°F) during the day. Rainfall during this period averages between 100mm (3.94") to 200mm (7.87") per month.

The months of September to November, akin to an autumn season, continue to experience relatively lower levels of rainfall, making this a continuation of the lesser rainy season. The humidity lessens slightly, although temperatures remain fairly consistent, oscillating between 23°C (73.4°F) and 31°C (87.8°F). Rainfall is comparatively lower, with monthly averages from 100mm (3.94") to 150mm (5.91").

In the tropical climes of French Guiana, December through February does not bring a winter chill. Instead, temperatures remain consistently warm, with lows around 23°C (73.4°F) and highs reaching up to 31°C (87.8°F). However, this period heralds the onset of the greater rainy season. Rainfall starts to increase during these months, averaging between 200mm (7.87") to 300mm (11.81") per month, accompanied by a surge in humidity. Despite this, the lush greenery and abundant wildlife make the landscape particularly vibrant during this season.

January falls within the greater rainy season in French Guiana, a period associated with increased precipitation levels across the country. Cayenne, the capital city located on the coast, receives an average rainfall of approximately 300mm (11.81") in January, with around 20 rainy days throughout the month. Weather in January »

February continues the greater rainy season in French Guiana, with precipitation levels remaining high across the country. The coastal city of Cayenne sees average rainfall around 300mm (11.81"), similar to January, with an average of 18 rainy days. Weather in February »

The month of March in French Guiana marks the continuing ascent towards the peak of the greater rainy season. The coastal capital city of Cayenne experiences an average rainfall of approximately 350mm (13.78"), a noticeable increase from the preceding months of January and February. Weather in March »

April in French Guiana signifies the peak of the greater rainy season, characterized by high levels of precipitation throughout the country. In Cayenne, the coastal capital, average rainfall amounts to approximately 400mm (15.75"), a substantial increase compared to March. Weather in April »

May in French Guiana is characterized by high precipitation as the greater rainy season begins to taper off. The coastal city of Cayenne records an average rainfall of approximately 350mm (13.78"), marginally less than the peak seen in April. Weather in May »

The month of June in French Guiana heralds a noticeable shift in weather patterns, as the country transitions from the greater rainy season to the lesser rainy season. In Cayenne, the coastal capital city, rainfall decreases significantly to an average of about 200mm (7.87"), almost half the amount recorded in May. Weather in June »

In French Guiana, the month of July marks the continuation of the lesser rainy season, with rainfall decreasing even further from the levels seen in June. The coastal capital of Cayenne experiences an average rainfall of approximately 150mm (5.91"), representing one of the driest months of the year. Weather in July »

August in French Guiana continues to showcase the characteristics of the lesser rainy season, with decreased precipitation levels being a prominent feature. In the coastal city of Cayenne, rainfall amounts average about 100mm (3.94"), a decrease from the previous month and one of the driest months of the year. Weather in August »

September in French Guiana marks a transition period as the country begins to move from the lesser rainy season back towards the greater rainy season. In Cayenne, the coastal capital, the average rainfall is about 100mm (3.94"), maintaining similar levels as in August. Weather in September »

October in French Guiana marks a distinctive shift towards the greater rainy season. In Cayenne, the coastal capital city, rainfall significantly increases, with an average of about 200mm (7.87"), a noticeable rise from September's figures. Weather in October »

In French Guiana, November indicates a further progression into the greater rainy season. In Cayenne, the coastal capital city, the average rainfall increases to about 250mm (9.84"), a further rise from October's levels. Correspondingly, the number of rainy days continues to increase, averaging 18 days throughout the month. Inland areas such as Saint-Laurent-du-Maroni mirror this trend, recording a surge in rainfall during November. Weather in November »

December in French Guiana is characterized by a continuation of the greater rainy season. In Cayenne, the coastal capital city, the average rainfall is about 300mm (11.81"), a further increase from November's levels. The number of rainy days also rises, with an average of approximately 20 days experiencing rainfall throughout the month. Inland regions such as Saint-Laurent-du-Maroni similarly experience high levels of rainfall during December, reflective of the pervasive influence of the greater rainy season across the entire country. Weather in December »