Cayenne climate

Name: Cayenne
Address: GF

Cayenne is warmest in October, with average highs of 31 °C, and coldest in July, when nights average 23 °C. May is the wettest month (395 mm) and September the driest (51 mm). Figures are 1991–2020 climate normals.

Across a full year Cayenne averages 2,528 mm of rain and 364 days above 25 °C.

French Guiana · population 61,550 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month October 31 °C
Coldest month July 23 °C
Driest month September 51 mm
Wettest month May 395 mm
Least cloud September 40 % cloud
Hottest on record October 34 °C
Coldest on record April 21 °C
Warmest sea July 28 °C

What to expectCayenne through the year

Cayenne changes little through the year. Average daily highs stay between 29 and 31 °C, so no month stands out as a season in the way it would further from the equator.

Counted across a normal year, 364 days a year reach 25 °C, 90 of them reach 30 °C. The warmest reading in the 1991–2020 record is 34 °C, in October.

Rain is strongly seasonal. May averages 395 mm against 51 mm in September — 7.7 times as much. Planning around the dry months matters more here than planning around temperature.

The sea off Cayenne is warmest in July at 28 °C and coldest in January at 27 °C. Sea temperature lags the air by a month or two, which is why late summer swims warmer than early summer at the same air temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	27.5 °C	249 mm	73 %
February	27.5 °C	203 mm	73 %
March	28.0 °C	169 mm	73 %
April	28.3 °C	258 mm	76 %
May	28.2 °C	395 mm	82 %
June	28.2 °C	367 mm	77 %
July	28.8 °C	243 mm	60 %
August	30.0 °C	122 mm	46 %
September	31.1 °C	51 mm	40 %
October	31.3 °C	58 mm	48 %
November	29.9 °C	150 mm	62 %
December	28.3 °C	263 mm	71 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C
January	27.5 °C	23.3 °C	25.1 °C	29.9 °C	21.3 °C	31	0
February	27.5 °C	23.5 °C	25.2 °C	30.2 °C	21.1 °C	28	0
March	28.0 °C	23.8 °C	25.5 °C	30.4 °C	21.5 °C	31	0
April	28.3 °C	23.8 °C	25.7 °C	31.4 °C	20.8 °C	30	0
May	28.2 °C	23.6 °C	25.5 °C	31.6 °C	21.9 °C	31	1
June	28.2 °C	23.2 °C	25.3 °C	33.5 °C	21.3 °C	30	1
July	28.8 °C	23.1 °C	25.6 °C	31.2 °C	21.3 °C	31	3
August	30.0 °C	23.7 °C	26.4 °C	33.0 °C	21.6 °C	31	16
September	31.1 °C	24.1 °C	27.1 °C	33.5 °C	20.8 °C	30	26
October	31.3 °C	24.3 °C	27.3 °C	34.2 °C	22.0 °C	31	28
November	29.9 °C	24.1 °C	26.5 °C	33.1 °C	21.7 °C	30	14
December	28.3 °C	23.6 °C	25.5 °C	32.2 °C	21.6 °C	31	2

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind	Sea temp
January	249 mm	25	12 h/day	73 %	86 %	18 km/h	26.9 °C
February	203 mm	22	12 h/day	73 %	84 %	19 km/h	26.9 °C
March	169 mm	23	12 h/day	73 %	82 %	19 km/h	27.1 °C
April	258 mm	24	12 h/day	76 %	85 %	18 km/h	27.3 °C
May	395 mm	28	12 h/day	82 %	88 %	16 km/h	27.6 °C
June	367 mm	28	12 h/day	77 %	89 %	14 km/h	27.9 °C
July	243 mm	26	12 h/day	60 %	86 %	13 km/h	28.2 °C
August	122 mm	18	12 h/day	46 %	82 %	14 km/h	28.1 °C
September	51 mm	10	12 h/day	40 %	77 %	15 km/h	27.9 °C
October	58 mm	11	12 h/day	48 %	77 %	16 km/h	28.1 °C
November	150 mm	19	12 h/day	62 %	82 %	16 km/h	27.8 °C
December	263 mm	26	12 h/day	71 %	86 %	17 km/h	27.3 °C

Where Cayenne ranks

Ranking	Position	Value
The warmest places in South America in October	45thof 50	31 °C

Planning a trip? See the best time to visit Cayenne.

QuestionsCommon questions about Cayenne’s climate

When is the best time to visit Cayenne?

That depends on what you want, so the honest answer is a comparison rather than a single month. January, February, June sit closest to 20 °C on average, October is the warmest month and September the driest. The month-by-month table above has the full picture.

How hot does Cayenne get?

In October, the warmest month, daily highs average 31 °C. About 90 days a year pass 30 °C. The highest value in the 1991–2020 record is 34 °C.

How cold does it get in winter?

Nights average 23 °C in July, the coldest month. Freezing nights are not part of a normal year here.

Which month is wettest in Cayenne?

May, averaging 395 mm over 28 days with rain. The driest month is September with 51 mm. The year as a whole averages 2,528 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Cayenne rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.