There are generally three climate zones in Kenya:
In the Kenyan highlands, which begin at an altitude of about 1,800 m, the rainy season lasts from April to June and from October to November. At this time of year it usually rains at night, in the afternoon or in the evening. The nights are cool. The coldest months in this region are July and August, when temperatures averaging 10°C are measured. The warmest months are January and February. The maximum temperatures measured during this time are about 25/26°C, the air humidity is within a tolerable range with 65 percent.
At Lake Victoria, however, higher temperatures are usually measured and more rain falls. On the coast, for example in Mombasa, the temperatures vary between 22 and 32°C, the average humidity is 75 percent. The months with the most frequent rainfalls are April to June. The driest and warmest months are January and February, the coolest months are July and August.
The best time to travel to Kenya is January/February, when there is almost no rain and warm temperatures. The months from March to May are also good months for travelling, as it is low season and you can still count on low prices and free rooms. However, you have to reckon with occasional heavy rain showers during this time.