Cayenne Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Cayenne, French Guiana. These values are calculated using 30 years of data (1990–2020) to ensure accuracy. Let's now guide you through the details for a complete overview.

Cayenne has a notably wet climate with abundant precipitation, recording 2591 mm (102 in) of rainfall per year. It does, however, have a distinct rainy season during certain months. Have a look at our detailed charts below to see how precipitation varies throughout the year.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

The seasons in Cayenne, bring significant changes in precipitation. The wettest month, May, receives heavy rainfall, with an average of 412 mm (16 in) of precipitation. This rainfall is distributed across 26 rainy days.

In contrast, the driest month, September, experiences much less rainfall, totaling 50 mm (2 in) over 4 rainy days. These distinct seasonal differences provide diverse experiences throughout the year.

May, the wettest month, has a maximum daytime temperature of 30°C (86°F). The city receives 119 hours of sunshine in this period. During the driest month September you can expect a temperature of 32°C (90°F). For more detailed insights into the city's temperatures, visit our Cayenne Temperature page.

Annual Rainfall in French Guiana: City Comparison

The map below shows the annual precipitation across French Guiana. You can also select the different months in case you are interested in a specific month.

Cayenne vs World: Rainfall Compared

Cayenne's average annual precipitation is 2591 mm (102 in). Let's compare this to some popular worldwide tourist destinations:

Chicago, USA, sees an annual precipitation of 1062 mm (42 in), with rain and snow contributing to its humid climate.

Meanwhile, Buenos Aires, Argentina, enjoys a humid subtropical climate with 1000 mm (39 in) of annual rainfall, mostly in the summer.

In Brisbane, Australia, the annual precipitation is 979 mm (39 in), making it wetter than Sydney.

Ho Chi Minh City, Vietnam, receives 1955 mm (77 in) of annual rainfall, with a pronounced wet season from May to November, typical of its tropical monsoon climate.

Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.

Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.

The proximity of a location to a large body of water can significantly affect its rainfall patterns:

• Ocean Influence: Coastal regions typically receive more rainfall due to the presence of moisture-laden winds from the ocean. These regions tend to have more humid climates and experience more frequent precipitation, especially in winter.
• Continental Climates: Areas further from the sea, such as inland or continental regions, experience less frequent rainfall and more extreme seasonal variations in precipitation.

• Mawsynram in India is noted as being the wettest place on earth, with over 11 meters (36 feet) of rain falling every year.
• In contrast, Antofagasta in Chile is among the driest places on the planet, getting less than 0.1mm (0.004 inches) per year, with some years recording virtually no rainfall.
• Nearly 1,650 thunderstorm cells are estimated over the planet at any given time.

For more detailed information about Cayenne's weather, including sunshine hours, humidity levels, and temperature data, visit our Cayenne Climate page.