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 90°F 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.

90
90°F max day temperature
8
8 hours of sunshine per day
4
4 days with some rainfall
73
73°F min night temperature
12
12 hours of daylight per day
VH
Very High heat & humidity
1.6
1.6 inches of monthly rainfall
11
11+ (Extreme) UV index
82
82°F 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

Travel Up: up to £25 off all holiday bookings

Discount Code

Save up to £25 on holidays with Travel Up
Book breaks across Europe, Asia & beyond
Valid on bookings over £750. Use promo code

Show discount code

******Y25

Redeem Travel Up discount code >>

Expires at 23:59 on Saturday 30th Nov 2024 · View all Travel Up 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) | Imperial (°F)

How hot is it in French Guiana in September?

Daytime temperatures usually reach 90°F in Cayenne, French Guiana in September with very high heat and humidity, falling to 73°F 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 82°F.

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 1.6 inches.

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