The city of Garoua was flooded by 400 millimetres of rain in just 24 hours [Al Jazeera]

40 centimetres of rain in 24 hours, that's a lot of rain.

This is what was reported by the northern Cameroon city of Garoua, between 12 GMT on 2 August and 12 GMT on the 3 August.

For a country as a whole, Cameroon isn't a stranger to heavy rains. In fact the country has seen an increase in droughts and floods over the past 30 years, with the extremes of climate becoming both more frequent and more severe. This obviously has a serious effect on the country both in terms of agriculture and the spread of diseases such as malaria and cholera.

However, the heaviest rainfall in the country is normally seen on the coast. Douala is right on the coastline and is the largest city in the country. It's where most of the major industries are located, from petroleum refineries to fishing, and yet the city has a phenomenal amount of rain.

Douala's wettest month is July, with an average rainfall of 742mm. The magnitude of this becomes clear when compared to London, which receives on average 611mm in an entire year!

Clearly it's a very wet city, and as it often receives its rainfall in the form of giant thunderstorms, this often leads to flooding. The problems are exacerbated by the fact that the drains are often clogged with rubbish.

However, this latest deluge wasn't seen in the Douala, but in Garoua in the north. This is normally a far drier part of the country, and lies in a region known for agriculture. The wettest month here is August, but the average rainfall is only 247.9mm.

This deluge of 400mm is therefore exceptional, and for all this rain to come in a 24-hour period would certainly give widespread, severe flooding.

Source: Al Jazeera