Last week, Nigeria was hit by severe flooding that has caused over 150 deaths so far. Heavy rain started on Wednesday night in the northern part of the country and continued into Thursday.
This made the Niger River overflow, forcing thousands of people to leave their homes and destroying hundreds of houses. Local leaders said this is the worst flood the region has seen in 60 years.
Heavy rain at this time of year is normal in Nigeria. The country has a tropical climate, and its wet season runs from April to October because of the West African monsoon.
This wet season happens due to the temperature differences between the land and the sea, and because of a weather pattern called the intertropical convergence zone (ITCZ). The ITCZ is a low-pressure band near the equator that moves north and south depending on the sun’s position.
From March to September, the sun shines more on the northern hemisphere. This heats the land faster than the ocean, creating low pressure over West Africa. This low pressure causes air to rise and pulls moist air in from the Atlantic Ocean. This moist air then falls as rain over the region.
During summer in the northern hemisphere, the ITCZ moves north, bringing more rain to northern Africa. In the winter, the ITCZ moves south, causing dry weather and higher pressure over West Africa.
This week, Niger and Nigeria will keep getting rain, but temperatures will be cooler than usual. The daytime temperatures will be about 10 degrees Celsius lower than normal, reaching the mid to high 20s Celsius instead of the usual mid to high 30s.
Northern Africa also faced unusual weather recently. On Saturday, Alexandria in Egypt was hit by a strong summer storm. The city had heavy rain, strong winds, and hail, which caused flooding and power outages.
The storm in Egypt was caused by a cold front connected to a low-pressure area that moved into the country over the weekend. This cold front brought moisture and pushed warm air upwards, forming storm clouds. Although storms often happen in Egypt during winter and spring, they are less common in summer.
