Cayenne, French Guiana climate

Am Tropical monsoon

Cayenne has a remarkably steady tropical climate (Tropical monsoon, Köppen Am). The hottest month is October with an average daily high near 33°C, while the coldest is January averaging around 23°C at night. Precipitation totals about 3400 mm a year and is strongly seasonal — May alone averages 570 mm while October barely receives 55 mm.

☀️ All year

Hot

Daytime highs near 33°C most of the year.

About 74 days a year above 32 °C

🌙 Nights

Stays warm

Even the coolest nights stay near 23°C.

🌧️ Rain

Very wet

About 3400 mm of rain a year.

Wettest in May

⛅ Sky & trend

Often cloudy

Cloudy skies much of the year.

+0.5 °C vs 50 years ago

Temperature & precipitation

Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figures

Hours of sunshine per day

Estimated sunny hours each month — daylight length × clear-sky fraction · 1991–2020 monthly cloud cover (NASA POWER)

Cayenne climate normals (1991–2020)

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	30	30	30	30	30	31	31	32	32	33	32	31
Avg temp (°C)	26	26	27	27	27	27	27	27	27	27	27	27
Avg low (°C)	23	23	24	24	24	23	22	22	22	22	23	23
Precipitation (mm)	389	339	302	441	570	384	259	139	59	55	133	331

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Avg high (°C)	30	30	30	30	30	31
Avg temp (°C)	26	26	27	27	27	27
Avg low (°C)	23	23	24	24	24	23
Precipitation (mm)	389	339	302	441	570	384

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Avg high (°C)	31	32	32	33	32	31
Avg temp (°C)	27	27	27	27	27	27
Avg low (°C)	22	22	22	22	23	23
Precipitation (mm)	259	139	59	55	133	331

How often — frequency of weather events

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	24	22	22	23	26	26	23	17	10	10	16	23
Days with high ≥ 32°C (days)	0.1	0.2	0.2	0.5	1	2	6	12	18	21	12	3

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Days with measurable rain (days)	24	22	22	23	26	26
Days with high ≥ 32°C (days)	0.1	0.2	0.2	0.5	1	2

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Days with measurable rain (days)	23	17	10	10	16	23
Days with high ≥ 32°C (days)	6	12	18	21	12	3

Sky & atmosphere

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	75	78	73	75	78	69	57	46	37	44	57	69
Relative humidity (%)	85	84	83	86	89	89	87	86	83	80	82	85
Wind speed (m/s)	2.2	2.4	2.3	2.2	2.0	1.7	1.6	1.7	1.8	1.8	1.9	2.1

Jan – Jun	Jan	Feb	Mar	Apr	May	Jun
Cloud cover (%)	75	78	73	75	78	69
Relative humidity (%)	85	84	83	86	89	89
Wind speed (m/s)	2.2	2.4	2.3	2.2	2.0	1.7

Jul – Dec	Jul	Aug	Sep	Oct	Nov	Dec
Cloud cover (%)	57	46	37	44	57	69
Relative humidity (%)	87	86	83	80	82	85
Wind speed (m/s)	1.6	1.7	1.8	1.8	1.9	2.1

Methodology & sources

Temperature & precipitation — 1991–2020 normals computed from 25 years of daily observations at Rochambeau, a weather station, about 12 km from the city centre. The underlying daily records come from NOAA's global station network.

Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.

How we build these numbers →