Kourou weather in September

In September, Kourou sees average daytime highs of 29°C and overnight lows near 25°C, with 40 mm of rain across 10 wet days and about 12 hours of daylight. It is the 2nd-warmest and 12th-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 61% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 06 min at the start of September to 12 hours by month's end. Set against the rest of the year, September is Kourou's 1st-clearest and 9th-windiest month. For the whole year in context, see Kourou's year-round climate.

Daytime high
29°
2nd warmest
Overnight low
25°
10th coldest
Rainfall
40 mm
10 wet days
Daylight
12 hours
6:24 AM – 6:26 PM
Cloud cover
38%
1st clearest
Wind
14 km/h
9th windiest
Solar energy
6.25 kWh/m²
Travel score
5.5
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 29°C through the month.

A typical September day in Kourou reaches about 29°C in the afternoon and slips back to 25°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 30°C. Set against its neighbours, September runs on par with August and on par with October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12925
22925
32925
42925
52925
62925
72925
82925
92925
102925
112925
122925
132925
142925
152925
162925
173025
183025
193025
203025
213025
223025
233025
243025
253025
263025
273025
283025
293025
303025

How September really feels in Kourou

Once humidity and wind are folded in, September averages 30 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
30
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Kourou weather by month

How September compares with the rest of the year at a glance. September is the 2nd-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 24°2362611.74.1
Feb27° / 24°19122.511.84.2
Mar28° / 25°16523.8124.3
Apr28° / 25°23625.312.14.0
May28° / 25°39228.912.23.6
Jun28° / 24°34628.712.33.4
Jul29° / 24°2042612.33.8
Aug29° / 25°9016.812.24.8
Sep29° / 25°4010125.5
Oct30° / 25°491211.95.2
Nov29° / 25°12820.411.84.2
Dec28° / 24°24426.911.73.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 61% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 20% of September, with mostly cloudy or overcast conditions the remaining 19%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
18218
28218
38218
48218
58119
68119
78119
88119
98119
108119
118119
128119
138119
148119
158119
168119
178119
188119
198218
208218
218218
228218
238218
248218
258218
268218
278218
288119
298020
308020

Chance of precipitation in September

Any precipitation

Kourou gets around 40 mm of rain over 10 wet days in September, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 34% and peaks near 37% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
137
237
336
436
536
636
736
836
936
1035
1135
1235
1335
1434
1534
1633
1733
1832
1932
2032
2132
2232
2332
2432
2532
2633
2733
2833
2934
3034

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the oppressive band about 79% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
18218
28218
38218
48119
58119
68119
78119
88119
98020
108020
118020
128020
138020
148020
158020
167921
177921
187921
197822
207822
217822
227723
237723
247723
257723
267723
277723
287723
297624
307624

Wind in September

Winds average 14 km/h in September.

Across September, daily wind ranges from about 13 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
113light breeze
213light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 06 min at the start of September to 12 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over September. Sunrise moves from 6:27 AM to 6:21 AM, and sunset from 6:33 PM to 6:19 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.16:276:33
212.16:276:33
312.16:276:32
412.16:276:32
512.16:266:31
612.16:266:31
712.16:266:30
812.16:266:30
912.16:266:29
1012.16:256:29
1112.16:256:28
1212.06:256:28
1312.06:256:27
1412.06:256:27
1512.06:246:26
1612.06:246:26
1712.06:246:25
1812.06:246:25
1912.06:236:24
2012.06:236:24
2112.06:236:23
2212.06:236:23
2312.06:226:22
2412.06:226:22
2512.06:226:21
2612.06:226:21
2712.06:226:20
2812.06:216:20
2912.06:216:19
3012.06:216:19

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.25 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 4.51 kWh/m² to a high of 6.25 kWh/m² in September across the year — September's 6.25 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
16.2Intense
26.2Intense
36.2Intense
46.2Intense
56.2Intense
66.2Intense
76.2Intense
86.2Intense
96.2Intense
106.2Intense
116.2Intense
126.2Intense
136.2Intense
146.2Intense
156.2Intense
166.2Intense
176.2Intense
186.2Intense
196.3Intense
206.3Intense
216.3Intense
226.3Intense
236.3Intense
246.3Intense
256.3Intense
266.3Intense
276.3Intense
286.3Intense
296.3Intense
306.3Intense
Planning a trip in September

Hazard calendar for Kourou

In seasonPeak

None of Kourou's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Kourou's rainy season runs April–July, when most of the year's rain falls.

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

Is September a good time to visit Kourou?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.5
Sightseeing
1st-best month of the year
7.2
Beach & pool
1st-best month of the year

September is a reasonable time to visit Kourou for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Kourou in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Kourou sees daytime highs around 29°C and nights near 25°C. Pack light clothes and sun protection. Worth having: rain gear. About 10 days see rain.

light clothessun protectionrain gear

Sea temperature near Kourou in September

The nearest coast averages about 28°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in July at about 28°C and coldest in January near 27°C.

The water stays above 20°C all year — warm enough for a swim any month.

26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb27Warm
Mar27Warm
Apr27Warm
May28Warm
Jun28Warm
Jul28Tropical
Aug28Tropical
Sep28Tropical
Oct28Tropical
Nov28Warm
Dec27Warm

UV index in Kourou in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Kourou peaks around April 11 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 11 at about 10 (extreme).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeApr 11UV 14Dec 11UV 10
UV index (midday)Level
Jan13Extreme
Feb13Extreme
Mar14Extreme
Apr14Extreme
May13Extreme
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec10Extreme

Air quality in Kourou in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Kourou is worst in February — around 28 µg/m³ PM2.5 (moderate), about 4.0× the cleanest month (August, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateFeb 1627 µg/m³Aug 157 µg/m³
PM2.5 (µg/m³)Level
Jan26Moderate
Feb28Moderate
Mar26Moderate
Apr26Moderate
May21Moderate
Jun12Moderate
Jul8Good
Aug7Good
Sep8Good
Oct10Good
Nov12Good
Dec21Moderate
Location & terrain

Where is Kourou?

Kourou sits at 5.2°N, 52.6°W, 7 m above sea level, in French Guiana. The nearest listed city is Cayenne, 42 km away.

CayenneMatouryRémire-MontjolySaint-Laurent-du-MaroniOiapoque

Topography around Kourou

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Kourou.

Within 3 km, the terrain around Kourou has only modest variations in elevation — a maximum elevation change of 67 m around an average of 4 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 165 m; within 80 km, significant variations in elevation — a maximum elevation change of 403 m.

The land around Kourou is covered by water (45%) within 3 km, water (47%) and trees (34%) within 16 km, and trees (57%) and water (37%) within 80 km.

3 km
67 m
16 km
165 m
80 km
403 m
treesgrasslandartificial surfaceswaterwetlandmangroves
September weather nearby: Cayenne 42 km · Matoury 50 km · Rémire-Montjoly 50 km · Saint-Laurent-du-Maroni 158 km · Oiapoque 172 km · Blauwgrond 284 km · Rainville 286 km · Beekhuizen 289 km

French Guiana travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / E
220 V · 50 Hz

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Kourou (5.1628°, -52.6427°, elevation 7 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).