For some climbers this question is almost irrelevant as they will have to fit their climb into whatever dates they can clear from their busy work or family schedules, though for perhaps the majority, this is probably the first question prospective climbers should ask themselves.
Before answering, however, it should be noted that Team Kilimanjaro is very happy to arrange a climb for you starting on any date, including all national and international holidays!
But the simple answer is that while Kilimanjaro can safely be climbed 365 days of the year, for the best weather trekkers are advised to aim to climb as close to the middle of these these periods as their circumstances allow:
Generally speaking - as the above recommendation suggests demonstrate - most climbers avoid climbing Kilimanjaro during the two rainy seasons each year. The main reason for this is that climbing in the rain is simply less enjoyable for some people and means missing out on many beautiful views and photographic opportunities.
For a few climbers however, there is an added attraction to climbing during rainy months because:
For most climbers however, the idea of minimising the likelihood of being often rained on and having the best prospects of good views and photo opportunities, are some of the deciding factors when deciding when to climb. Because Team Kilimanjaro is aware of these trends we have long sought methods to ensure that our climbers are not exposed to high volume crowding and that they should enjoy as authentic a wilderness experience as possible, despite climbing at a very busy time.
As well as trying to incorporate some of the best pro-acclimatisation topographical features as possible, our desire to avoid crowds has driven us to develop unique routes that are exclusive to us and which we believe offer the best possible experiences and summit prospects on Kilimanjaro. This means that even if choosing or needing to climb at a time of year when the highest volumes of climbers on Kilimanjaro can be expected, Team Kilimanjaro are reasonably confident of ensuring that you are not likely to suffer from crowds and that you can enjoy the vast majority of the trail at your pace, without leap-frogging other groups or being jostled by their support staff.
For those climbing one of TK's customised, crowd-avoiding routes that also happen to have the best acclimatisation and least unnecessary depletion of precious summit reserves, the ideal months to climb Kilimanjaro if wanting to avoid the worst of the rains, are usually considered to be: