Onitsha weather in September

In September, Onitsha sees average daytime highs of 30°C and overnight lows near 24°C, with 200 mm of rain across 26.8 wet days and about 12 hours of daylight. It is the 10th-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 1% 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 Onitsha's 11th-clearest and 9th-windiest month. For the whole year in context, see Onitsha's year-round climate.

Daytime high
30°
10th warmest
Overnight low
24°
3rd coldest
Rainfall
200 mm
26.8 wet days
Daylight
12 hours
6:26 AM – 6:28 PM
Cloud cover
84%
11th clearest
Wind
7 km/h
9th windiest
Solar energy
3.91 kWh/m²
Travel score
3.0
out of 10

Onitsha is A City in Anambra state Nigeria.

Density
42,912/km²
people per km²
Founded
1550

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 30°C through the month.

A typical September day in Onitsha reaches about 30°C in the afternoon and slips back to 24°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 31°C. Set against its neighbours, September runs on par with August and about 1°C cooler than October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12923
22923
32923
42923
52923
62923
72924
82924
92924
102924
112924
122924
133024
143024
153024
163024
173024
183024
193024
203024
213024
223024
233024
243024
253024
263024
273024
283024
293024
303024

How September really feels in Onitsha

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.

Onitsha weather by month

How September compares with the rest of the year at a glance. September is the 10th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan35° / 24°51.111.73.1
Feb36° / 25°132.911.82.5
Mar35° / 25°479.6122.5
Apr33° / 25°9516.112.12.7
May32° / 25°14223.112.32.7
Jun30° / 24°18425.512.33.0
Jul29° / 23°1782612.33.3
Aug29° / 23°17723.212.23.6
Sep30° / 24°20026.8123.0
Oct31° / 24°15523.111.93.2
Nov32° / 24°295.711.74.2
Dec34° / 24°4111.63.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 1% 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 (%)
1694
2694
3694
4694
5694
6694
7694
8793
9793
10793
11793
12793
13892
14892
15892
16793
17892
18892
19892
20991
21991
22991
231090
241090
251090
261090
271189
281189
291189
301189

Chance of precipitation in September

Any precipitation

Onitsha gets around 200 mm of rain over 26.8 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 88% and peaks near 90% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
186
287
387
488
589
689
789
890
990
1090
1190
1290
1390
1490
1590
1689
1789
1889
1989
2088
2188
2288
2388
2488
2587
2687
2787
2887
2986
3086

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 98% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
1991
2991
3991
4991
5991
6991
7991
8991
9991
10991
11991
12991
13991
14991
15991
16991
17991
18982
19982
20982
21982
22982
23982
24973
25973
26973
27964
28955
29955
30946

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
197calm
207calm
217calm
227calm
237calm
247calm
256calm
266calm
276calm
286calm
296calm
306calm

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 6:29 AM to 6:24 AM, and sunset from 6:36 PM to 6:21 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.16:296:36
212.16:296:36
312.16:296:35
412.16:286:35
512.16:286:34
612.16:286:34
712.16:286:33
812.16:286:33
912.16:286:32
1012.16:276:31
1112.16:276:31
1212.16:276:30
1312.16:276:30
1412.06:276:29
1512.06:266:29
1612.06:266:28
1712.06:266:28
1812.06:266:27
1912.06:266:27
2012.06:256:26
2112.06:256:25
2212.06:256:25
2312.06:256:24
2412.06:256:24
2512.06:246:23
2612.06:246:23
2712.06:246:22
2812.06:246:22
2912.06:246:21
3012.06:246:21

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.91 kWh/m².

For context, solar energy here swings from a low near 3.75 kWh/m² to a high of 5.5 kWh/m² in January across the year — September's 3.91 kWh/m² sits near the bottom.

01234151015202530
Solar energy (kWh/m²)Level
13.8Moderate
23.8Moderate
33.8Moderate
43.8Moderate
53.8Moderate
63.8Moderate
73.9Moderate
83.9Moderate
93.9Moderate
103.9Moderate
113.9Moderate
123.9Moderate
133.9Moderate
143.9Moderate
153.9Moderate
163.9Moderate
173.9Moderate
183.9Moderate
194.0Moderate
204.0Moderate
214.0Moderate
224.0Moderate
234.0Moderate
244.0Moderate
254.0Moderate
264.0Moderate
274.0Moderate
284.0Moderate
294.0Moderate
304.0Moderate
Planning a trip in September

Hazard calendar for Onitsha

In seasonPeak

In September, Onitsha sits inside its monsoon season. The full year is below, with each hazard's peak months called out.

Onitsha's monsoon runs April–October, when most of the year's rain falls.

Onitsha sees seasonal dust haze (December–April), heaviest in February.

Monsoon
Dust
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Onitsha?

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

3.0
Sightseeing
7th-best month of the year
4.0
Beach & pool
12th-best month of the year

September is a weaker month for outdoor sightseeing in Onitsha.

What to pack for Onitsha in September

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

In September, Onitsha sees daytime highs around 30°C and nights near 24°C. Pack light clothes and rain gear. About 27 days see rain.

light clothesrain gear

UV index in Onitsha 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 Onitsha peaks around September 22 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 10 at about 8 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highExtremeVery highSep 22UV 12Jan 10UV 8
UV index (midday)Level
Jan8Very high
Feb10Very high
Mar12Extreme
Apr12Extreme
May11Extreme
Jun11Extreme
Jul10Extreme
Aug9Very high
Sep12Extreme
Oct12Extreme
Nov10Very high
Dec8Very high

Air quality in Onitsha 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 Onitsha is worst in January — around 201 µg/m³ PM2.5 (very unhealthy), about 3.5× the cleanest month (August, 58 µg/m³).

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

0306090120150180210JanFebMarAprMayJunJulAugSepOctNovDecVery unhealthyUnhealthyVery unhealthyJan 11201 µg/m³Aug 1058 µg/m³
PM2.5 (µg/m³)Level
Jan201Very unhealthy
Feb171Very unhealthy
Mar100Unhealthy
Apr98Unhealthy
May83Unhealthy
Jun73Unhealthy
Jul59Unhealthy
Aug58Unhealthy
Sep70Unhealthy
Oct92Unhealthy
Nov108Unhealthy
Dec197Very unhealthy
Location & terrain

Where is Onitsha?

Onitsha sits at 6.1°N, 6.8°E, 57 m above sea level, in Nigeria. The nearest listed city is Nkpor, 5.0 km away.

Topography around Onitsha

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

Within 3 km, the terrain around Onitsha has only modest variations in elevation — a maximum elevation change of 131 m around an average of 54 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 222 m; within 80 km, significant variations in elevation — a maximum elevation change of 531 m.

The land around Onitsha is covered by artificial surfaces (70%) within 3 km, trees (45%) and artificial surfaces (23%) within 16 km, and trees (66%) and grassland (21%) within 80 km.

3 km
131 m
16 km
222 m
80 km
531 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Nkpor 5.0 km · Asaba 8.0 km · Atani 16 km · Nnewi 21 km · Ozubulu 23 km · Enugu-Ukwu 24 km · Ogwashi-Uku 29 km · Igbo-Ukwu 30 km

Nigeria travel facts

Travel advisory
Level 3
Reconsider Travel
Power plugs
Type D / G
230 V · 50 Hz
Prices
≈ 13% of US
price level, 2025
GDP per capita
$1,224
2025
Happiness
4.8 / 10
World Happiness, 2025
Safe drinking water
30%
of population, 2024
Homicide rate
15.7
per 100k, 2023
Road deaths
20.7
per 100k/yr, 2019
Income group
Lower middle
World Bank
English
High
EF EPI 569
Religion
Muslim 54%other Christian 35%Roman Catholic 11%other 1%

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 Onitsha (6.1498°, 6.7857°, elevation 57 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).