Climate averages 1991–2020
Onitsha weather
in September.
A hot, very wet month: the 10th warmest and the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Onitsha: daytime highs average 28.7°C and nights cool to about 23.0°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 200 mm of rain on roughly 27 days, which makes September a very wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 12 h 09 min on an average September day.
The nearest other city in this atlas is Nkpor (5 km away). In September its highs average 28.4°C, about as warm as Onitsha, with 200 mm of rain.
Among the 143 cities listed in Nigeria, Onitsha ranks joint 45th of 143 for the warmest September highs and joint 58th of 143 for the driest September (rainfall, lowest first). The mean September high of those 143 cities is 28.6°C; Onitsha is 0.1°C warmer than that mean.
From September to October, average highs rise by 0.6°C to 29.3°C, and monthly rainfall falls from 200 mm to 155 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Onitsha climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 34.4°C23.2°C | 23.2°C | 5.1 | 1.1 | 11.812 h |
| February | 34.9°C24.3°C | 24.3°C | 14 | 2.9 | 11.912 h |
| March | 33.8°C24.7°C | 24.7°C | 47 | 9.5 | 12.112 h |
| April | 32.1°C24.5°C | 24.5°C | 95 | 16.0 | 12.312 h |
| May | 30.6°C24.0°C | 24.0°C | 142 | 23.0 | 12.412 h |
| June | 29.0°C23.3°C | 23.3°C | 184 | 25.5 | 12.512 h |
| July | 28.2°C22.8°C | 22.8°C | 178 | 25.9 | 12.412 h |
| August | 28.3°C22.7°C | 22.7°C | 177 | 23.2 | 12.312 h |
| September, selected | 28.7°C23.0°C | 23.0°C | 200 | 26.8 | 12.212 h |
| October | 29.3°C23.2°C | 23.2°C | 155 | 23.1 | 12.012 h |
| November | 30.8°C23.4°C | 23.4°C | 29 | 5.6 | 11.812 h |
| December | 33.1°C23.3°C | 23.3°C | 4.3 | 0.9 | 11.812 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Nkpor in SeptemberNigeria · 5 kmHigh 28.4°C · Low 22.7°C · 200 mm rain
- Asaba in SeptemberNigeria · 8 kmHigh 28.9°C · Low 23.2°C · 200 mm rain
- Atani in SeptemberNigeria · 16 kmHigh 28.8°C · Low 22.9°C · 212 mm rain
- Nnewi in SeptemberNigeria · 21 kmHigh 28.2°C · Low 22.3°C · 279 mm rain
- Igbo-Ukwu in SeptemberNigeria · 30 kmHigh 27.1°C · Low 21.1°C · 279 mm rain
- Agulu in SeptemberNigeria · 31 kmHigh 28.3°C · Low 22.2°C · 279 mm rain
- Awka in SeptemberNigeria · 32 kmHigh 28.8°C · Low 22.8°C · 222 mm rain
- Ihiala in SeptemberNigeria · 34 kmHigh 28.1°C · Low 22.2°C · 282 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Onitsha) is explained once on the Onitsha year overview and on the Sources, method and limits page.
Nkpor and Asaba lie in the same rainfall cell, so their rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.