There are two distinct rainy seasons that occur in Nairobi, one in the spring months of March to May, which is locally referred to as the 'long rainy' season. April is the wettest month during this period bringing upwards of eight inches of rain on average.

The relatively cool season, from late-June to October, gets much less rain. There's a second rainy season, the 'short rains', for a few weeks in November and December, followed roughly from mid-December to March by a dry season of hot, usually rainless, weather.