Oyam weather in September

In September, Oyam sees average daytime highs of 29°C and overnight lows near 22°C, with 104 mm of rain across 19.9 wet days and about 12 hours of daylight. It is the 9th-warmest and 9th-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 0% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 hours at the start of September to 12 hours by month's end. Set against the rest of the year, September is Oyam's 5th-clearest and 2nd-windiest month. For the whole year in context, see Oyam's year-round climate.

Daytime high
29°
9th warmest
Overnight low
22°
4th coldest
Rainfall
104 mm
19.9 wet days
Daylight
12 hours
6:12 AM – 6:12 PM
Cloud cover
82%
5th clearest
Wind
7 km/h
2nd windiest
Solar energy
3.79 kWh/m²
Travel score
3.9
out of 10

Oyam is place in Moyen-Ogooué Province, Gabon.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

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 Oyam reaches about 29°C in the afternoon and slips back to 22°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 31°C. Set against its neighbours, September runs about 2°C warmer than August and about 1°C cooler than October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12822
22822
32822
42922
52922
62922
72922
82922
92922
102922
112922
122922
132922
142922
152922
162922
172922
182923
192923
203023
213023
223023
233023
243023
253023
263023
273023
283023
293023
303023

How September really feels in Oyam

Once humidity and wind are folded in, September averages 19 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
19
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.

Oyam weather by month

How September compares with the rest of the year at a glance. September is the 9th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 23°16526.2122.8
Feb31° / 23°15723.9122.6
Mar31° / 23°22227.5122.5
Apr31° / 23°22026.5122.6
May31° / 23°19327122.8
Jun29° / 22°5911.8125.2
Jul27° / 21°225.8126.5
Aug28° / 22°266.9126.2
Sep29° / 22°10419.9123.9
Oct30° / 23°25529.3122.7
Nov30° / 23°29329.3122.6
Dec30° / 23°22328.4122.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 0% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 8% of September, with mostly cloudy or overcast conditions the remaining 92%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1496
2496
3595
4595
5595
6694
7694
8694
9793
10793
11793
12892
13892
14892
15892
16991
17991
18991
191090
201090
211090
221090
231090
241090
251189
261189
271189
281189
291189
301189

Chance of precipitation in September

Any precipitation

Oyam gets around 104 mm of rain over 19.9 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 67% and peaks near 87% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
139
240
342
444
546
648
750
853
955
1058
1160
1263
1365
1467
1569
1671
1773
1875
1977
2078
2179
2280
2381
2482
2583
2684
2785
2885
2986
3087

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 84% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)
14159
23961
33763
43466
53268
63070
72773
82575
92377
102179
111981
121783
131585
141387
151288
161189
17991
18892
19892
20793
21694
22694
23694
24595
25595
26496
27496
28496
29397
30397

Wind in September

Winds average 7 km/h in September.

Across September, daily wind ranges from about 6 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

Sunrise & sunset in September

DaylightNight

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

Days grow by about 0 minutes over September. Sunrise moves from 6:17 AM to 6:07 AM, and sunset from 6:17 PM to 6:07 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.06:176:17
212.06:176:17
312.06:166:16
412.06:166:16
512.06:166:16
612.06:156:15
712.06:156:15
812.06:156:14
912.06:146:14
1012.06:146:14
1112.06:146:13
1212.06:136:13
1312.06:136:13
1412.06:126:12
1512.06:126:12
1612.06:126:12
1712.06:116:11
1812.06:116:11
1912.06:106:10
2012.06:106:10
2112.06:106:10
2212.06:096:09
2312.06:096:09
2412.06:096:09
2512.06:086:08
2612.06:086:08
2712.06:086:08
2812.06:076:07
2912.06:076:07
3012.06:076:07

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.79 kWh/m².

For context, solar energy here swings from a low near 3.22 kWh/m² to a high of 4.88 kWh/m² in March across the year — September's 3.79 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
13.5Moderate
23.5Moderate
33.5Moderate
43.6Moderate
53.6Moderate
63.6Moderate
73.6Moderate
83.7Moderate
93.7Moderate
103.7Moderate
113.7Moderate
123.8Moderate
133.8Moderate
143.8Moderate
153.8Moderate
163.8Moderate
173.8Moderate
183.9Moderate
193.9Moderate
203.9Moderate
213.9Moderate
223.9Moderate
233.9Moderate
244.0Moderate
254.0Moderate
264.0Moderate
274.0Bright
284.0Bright
294.0Bright
304.0Bright
Planning a trip in September

Is September a good time to visit Oyam?

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

3.9
Sightseeing
4th-best month of the year
5.0
Beach & pool
4th-best month of the year

September is a weaker month for outdoor sightseeing in Oyam.

What to pack for Oyam in September

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

In September, Oyam sees daytime highs around 29°C and nights near 22°C. Pack light clothes and rain gear. About 20 days see rain.

light clothesrain gear

UV index in Oyam 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 Oyam peaks around March 20 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 21 at about 9 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeMar 20UV 14Jun 21UV 9
UV index (midday)Level
Jan12Extreme
Feb12Extreme
Mar14Extreme
Apr13Extreme
May11Extreme
Jun9Very high
Jul9Very high
Aug10Very high
Sep12Extreme
Oct13Extreme
Nov12Extreme
Dec10Very high

Air quality in Oyam 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 Oyam is worst in February — around 41 µg/m³ PM2.5 (poor), about 2.3× the cleanest month (October, 18 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorModerateFeb 1340 µg/m³Oct 1418 µg/m³
PM2.5 (µg/m³)Level
Jan35Moderate
Feb41Poor
Mar31Moderate
Apr26Moderate
May26Moderate
Jun32Moderate
Jul31Moderate
Aug26Moderate
Sep20Moderate
Oct18Moderate
Nov22Moderate
Dec30Moderate
Location & terrain

Where is Oyam?

Oyam sits at 0.2°S, 10.7°E, 72 m above sea level, in Gabon. The nearest listed city is Lambaréné, 74 km away.

LambarénéNtoumOwendoLibrevilleAkandaMouilaCiudad de la PazPort-Gentil

Topography around Oyam

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

Within 3 km, the terrain around Oyam has significant variations in elevation — a maximum elevation change of 283 m around an average of 116 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 442 m; within 80 km, large variations in elevation — a maximum elevation change of 1,018 m.

The land around Oyam is covered by trees (97%) within 3 km, trees (97%) within 16 km, and trees (99%) within 80 km.

3 km
283 m
16 km
442 m
80 km
1,018 m
treesbare terrainwater
September weather nearby: Lambaréné 74 km · Ntoum 122 km · Owendo 142 km · Libreville 152 km · Akanda 175 km · Mouila 190 km · Ciudad de la Paz 200 km · Port-Gentil 219 km

Gabon travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / E
220 V · 50 Hz
Prices
≈ 37% of US
price level, 2025
GDP per capita
$8,263
2025
Happiness
5.2 / 10
World Happiness, 2025
Road deaths
23.9
per 100k/yr, 2019
Income group
Upper middle
World Bank
Religion
Protestant 46%Roman Catholic 30%Muslim 11%none 7%

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 Oyam (-0.2°, 10.6833°, elevation 72 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. 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).