Onitsha climate
Onitsha (Nigeria) has a tropical savanna (dry winter) climate (Köppen Aw). The average temperature over the year is 26 °C79 °F, and about 1,705 mm67 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Onitsha climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 3086 | 2068 | 2577 | 120.5 |
| Feb | 3187 | 2272 | 2780 | 291.1 |
| Mar | 3187 | 2475 | 2781 | 612.4 |
| Apr | 3086 | 2475 | 2781 | 1234.8 |
| May | 3085 | 2475 | 2780 | 1676.6 |
| Jun | 2983 | 2374 | 2678 | 2278.9 |
| Jul | 2883 | 2272 | 2577 | 2319.1 |
| Aug | 2883 | 2272 | 2577 | 2429.5 |
| Sep | 2883 | 2373 | 2578 | 31512 |
| Oct | 2983 | 2373 | 2678 | 2108.3 |
| Nov | 3085 | 2373 | 2679 | 732.9 |
| Dec | 3086 | 2169 | 2577 | 150.6 |
| Year | 3187 | 2068 | 2679 | 1,70567 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 72% | 42% | 5.0 | 11:48 |
| Feb | 79% | 60% | 4.7 | 11:55 |
| Mar | 85% | 75% | 4.8 | 12:04 |
| Apr | 87% | 79% | 4.9 | 12:15 |
| May | 89% | 77% | 4.8 | 12:24 |
| Jun | 90% | 79% | 4.3 | 12:29 |
| Jul | 90% | 86% | 3.9 | 12:27 |
| Aug | 89% | 87% | 3.9 | 12:19 |
| Sep | 90% | 85% | 4.1 | 12:09 |
| Oct | 90% | 77% | 4.6 | 11:58 |
| Nov | 85% | 56% | 5.0 | 11:50 |
| Dec | 75% | 41% | 5.0 | 11:46 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Onitsha is like
The warmest month is March, with an average high of 31 °C87 °F and a low of 24 °C75 °F. The coldest is January, when highs average 30 °C86 °F and lows 20 °C68 °F. Temperatures barely change through the year: the warmest and the coolest month differ by only 2.4 °C4.3 °F.
It is wet, with about 1,705 mm67 in of precipitation per year. The wettest three-month stretch is July–September, which brings 46% of the annual total. Months with less than 20 mm0.8 in on average: December and January. The wettest month is September (315 mm12 in), the driest is January (12 mm0.5 in).
Relative humidity ranges from 72% in January to 90% in September. The clearest skies (lowest average cloud amount, 41%) are typical of December. Average wind speed near the ground ranges from 4 km/h (3 mph) in November to 8 km/h (5 mph) in August.
Best time to visit Onitsha
Based on these averages, the most comfortable months for sightseeing and outdoor activities are December and January: average highs of 30 °C86 °F to 30 °C86 °F with 12 mm0.5 in to 15 mm0.6 in of precipitation per month.
The most challenging month is September, which is very wet (315 mm12 in) and humid (90% relative humidity).
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
Onitsha weather by month
- January30 °C86 °F / 20 °C68 °F
- February31 °C87 °F / 22 °C72 °F
- March31 °C87 °F / 24 °C75 °F
- April30 °C86 °F / 24 °C75 °F
- May30 °C85 °F / 24 °C75 °F
- June29 °C83 °F / 23 °C74 °F
- July28 °C83 °F / 22 °C72 °F
- August28 °C83 °F / 22 °C72 °F
- September28 °C83 °F / 23 °C73 °F
- October29 °C83 °F / 23 °C73 °F
- November30 °C85 °F / 23 °C73 °F
- December30 °C86 °F / 21 °C69 °F
What to pack for Onitsha
- Wetter months (May–October) — highs 2883 to 30 °C85 °F, lows 2272 to 24 °C75 °F, about 232 mm9.1 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses and a good rain jacket or umbrella and quick-drying shoes.
- Drier months (November–April) — highs 3085 to 31 °C87 °F, lows 2068 to 24 °C75 °F, about 52 mm2.0 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water.
How Onitsha compares
Compared with Benin City, about 130 km to the west, Onitsha is on average 0.4 °C0.8 °F warmer and receives a similar amount of precipitation. The difference is largest in August (0.6 °C1.1 °F warmer).
Of the 74 places in Nigeria covered by World Climates, Onitsha is the 29th warmest by annual mean temperature and the 20th wettest by annual precipitation. See all of them on the Nigeria climate page.
Places in other countries with the most similar temperature and rainfall pattern (seasons shifted for the other hemisphere where needed): Man (Ivory Coast, Aw), Séguéla (Ivory Coast, Aw) and Rio Branco (Brazil, Aw).
The same NASA POWER grid cell also contains Atani (pop. 230,000), Nnewi (pop. 193,987) and Nkpor (pop. 103,733). Their long-term averages in this dataset are essentially the same as for Onitsha, so they do not have separate pages.
Nearby places
- Awka 32 km · 26 °C78 °F · 1,705 mm67 in
- Okigwe 72 km · 25 °C77 °F · 1,653 mm65 in
- Owerri 79 km · 26 °C78 °F · 1,841 mm72 in
- Uromi 79 km · 24 °C75 °F · 1,595 mm63 in
- Enugu 85 km · 25 °C77 °F · 1,526 mm60 in
- Nsukka 104 km · 24 °C75 °F · 1,368 mm54 in
- Umuahia 105 km · 25 °C77 °F · 1,791 mm70 in
- Amaigbo 123 km · 26 °C78 °F · 1,714 mm67 in
Frequently asked questions
What is the warmest month in Onitsha?
March is the warmest month in Onitsha, with an average high of 31 °C (87 °F) and an average low of 24 °C (75 °F).
What is the coldest month in Onitsha?
January is the coldest month, with an average high of 30 °C (86 °F) and an average low of 20 °C (68 °F).
When does it rain the most in Onitsha?
September is the wettest month with about 315 mm (12.4 in) of precipitation; January is the driest with about 12 mm (0.5 in).
What is the best time to visit Onitsha?
Judging by long-term averages, the most comfortable months are December and January.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.