There are two distinct trekking seasons which constitute the best time to climb Kilimanjaro. They are January-March and June-October.
Best Trekking Months for Kilimanjaro
January-March is generally colder than June-October and there is a higher probability of encountering snow on the summit. For some this might be seen as a negative, but the benefits of a January-March trek is that the slopes are often quieter at this time of the year.
The June-October trekking season coincides with the summer holidays in Europe and N.America and hence certain routes are often quite busy.
March, April and November are the wettest months on Kilimanjaro, and not ideal of trekking.
Snow fall and cold temperatures