Climate zone: tropics
High humidity in French Guiana and high temperatures are causing a pleasant weather at times, but also and partly tropical hot and humid. It is yearlong warm or hot. Dued to the lesser rain the best time for traveling is from August to November. Most precipitation decrease from January to June.
› Duration of daylight and sunshine in French Guiana
hours of sunshine per day rainy days per month Precipitation in mm/day Relative humidity in % Absolute humidity in g/m³ (approx.)
Temperature records of the last 69 years
The hottest temperature measured from 1950 to December 2019 was reported by the Saint Laurent Du Maroni weather station. In September 2016 the record temperature of 38.0 °C was reported here. The hottest summer from July to September, based on all 4 weather stations in French Guiana below 110 metres altitude, was recorded in 1998 with an average temperature of 27.0 °C. This average temperature will normally be measured every 4 to 6 hours, thus also including the nights. Normally, this value is 26.4 degrees Celsius. The average maximum daily temperature at that time was 32.6 °C.
The coldest day in these 69 years was reported by the weather station Saint Laurent Du Maroni. Here the temperature dropped to 18.7 °C in January 2016. Saint Laurent Du Maroni lies at an altitude of 5 meters above sea level. The coldest winter (January to March) was in 1971 with an average temperature of 24.8 °C. In French Guiana, it is usual to have about 1.0 degrees more at 25.8 °C for this three-month period.
Long-term development of temperatures from 1996 - 2019
In contrast to single record values, a long-term development cannot simply be brought about by all weather stations in the country. Both the number and the locations are constantly changing. A simply calculated average value would give a falsified result. If several measuring stations in particularly cold mountain or coastal regions are added in one year, the average would already decrease as a result of this alone. If a station fails during the summer or winter months, it does not provide any values and falsifies the average again. The subsequent long-term development was therefore reduced to only 2 measuring points in order to have actually comparable data over as long a period as possible.
In the years 1996 to 2019 there were only these 2 weather stations in the whole country, which reported continuous temperature values (Cayenne Matoury, St Georges De L'oyapock). From these weather reports we have created a long-term development that shows the monthly average temperatures. The hottest month in this entire period was September 2017 with 27.7 °C. Januar 2000 was the coldest month with an average temperature of 24.8 °C.
The average annual temperature was about 26.1 °C in the years after 1996 and about 26.4 °C in the last years before 2019. So over the past 24 years it has only increased by a minimal 0.4 °C. This trend only applies to the selected 2 weather stations in French Guiana. A considerably more comprehensive evaluation of the global warming
has been provided separately.
More detailed information on global warming with a view by continent can also be found on our topic page on climate change