Weather will likely play an important role when you plan your trip to Monrovia, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually January and April, with an average temperature of 27°C, while the coldest months are August and September, with an average of 25°C. The rainiest months in Monrovia are September, June, August and July, with each month seeing an average of 608 mm of rainfall.