French Guiana weather in September 2025

Q: How hot is it in French Guiana in September?

Daytime temperatures usually reach 32°C in Cayenne, French Guiana in September with very high heat and humidity, falling to 23°C at night.

Q: How sunny is it in French Guiana in September?

There are normally 8 hours of bright sunshine each day in Cayenne, French Guiana in September - that's 68% of daylight hours.

Q: How warm is the sea around French Guiana in September?

The average sea temperature around Cayenne, French Guiana in September is 28°C.

Q: Does it rain in French Guiana in September?

There are usually 4 days with some rain in Cayenne, French Guiana in September and the average monthly rainfall is 40mm.

Expect 32°C daytime maximum temperatures in the shade with on average 8 hours of sunshine per day in French Guiana in September. Check more long-term weather averages for French Guiana in September before you book your next holiday to French Guiana in 2025/2026.

32
32°C max day temperature
8
8 hours of sunshine per day
4
4 days with some rainfall
23
23°C min night temperature
12
12 hours of daylight per day
VH
Very High heat & humidity
40
40 mm of monthly rainfall
11
11+ (Extreme) UV index
28
28°C sea temperature

More about French Guiana

French Guiana by month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Recommended for French Guiana

Carrentals.co.uk: Car hire offers from £5 a day

Sale

Find car hire worldwide from as little as £1 a day
Book car hire with no hidden costs & best price guarantee
Free cancellation up to 48 hours before pickup

Go to Carrentals.co.uk deal >>

View all Carrentals.co.uk offers

The September weather guide for French Guiana, represented by Cayenne, (Cayenne) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Metric (°C / mm) | Imperial (°F / inches)

How hot is it in French Guiana in September?

Daytime temperatures usually reach 32°C in Cayenne, French Guiana in September with very high heat and humidity, falling to 23°C at night.

How sunny is it in French Guiana in September?

There are normally 8 hours of bright sunshine each day in Cayenne, French Guiana in September - that's 68% of daylight hours.

How warm is the sea around French Guiana in September?

The average sea temperature around Cayenne, French Guiana in September is 28°C.

Does it rain in French Guiana in September?

There are usually 4 days with some rain in Cayenne, French Guiana in September and the average monthly rainfall is 40mm.

French Guiana September sunrise & sunset times

Browse the sunrise and sunset times for French Guiana in September 2025. Select a month to view French Guiana sunrise and sunset times for the next 12 months. The French Guiana sunrise and sunset times shown below are for Cayenne.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec