August in Monrovia is the windiest and the coldest month of the year. In August, the weather in Monrovia is typically warm. Average daily high temperature in August is about 26 degrees above zero. On average, Monrovia has 29 rainy and 2 partly cloudy days in August. The rains are usually heavy. August as well as January, February, March, and April is considered the most uncomfortable time to visit Monrovia.