Liberian rivers are short, flowing parallel to one another from the mountains to the Atlantic Ocean. The largest rivers are the Saint Paul also called Corbaa, Saint John also known as Meah, Mano also called Bewa, Cestos also known as Nuon, Loffa and Cavalla also known as Yuu. Cavalla which forms the eastern boundary of Liberia between Liberia and Côte d’Ivoire is the longest.
The climate is hot and humid. Temperature varies around the country but it averages about 80 degree Fahrenheit. The relative humidity also varies but can be up to 90 percent along the coastline where rainfalls are heavy. The combination of high temperature and high relative humidity make most days hot and sticky, especially along the coastline. Temperature and relative humidity are lower in the interior than along the coastal region.
There are two seasons: Rainy and dry. Rainy season begins in May and ends in October with a short interlude around July or August. Dry season begins in November and ends in April. For a few days around Christmas, temperature and relative humidity drop when dust-laden wind known as Harmattan blows from the Sahara Region, bringing cold winter air. There are indications that the rain pattern is changing due to climate change.