Due to Tanzania's proximity to the equator, with its landmass ranging from 1°-11.45° south and 29.20°-40.35° east, this region does not experience the extremes of winter and summer weather, but has dry and wet seasons instead. The local weather conditions on Kilimanjaro can be somewhat unpredictable to say the very least. Rainfall varies from 2100 mm per year in the rainforest belt to less than 120 mm per year in the summit zone. Similarly, daily temperature changes are unexpected when compared to normal weather cycles, and are largely dependent on altitude.
Mount Kilimanjaro has five major ecological zones, each approximately 3,280 feet (1,000 m) in altitude. Each zone is subject to a corresponding decrease in rainfall, temperature and life as the altitude increases. At the beginning of the climb, at the base of the mountain, the average temperature is around 70°F to 80°F (27°C to 32°C). From there, the temperatures will decrease as you move through Mount Kilimanjaro's ecological zones. At the summit, Uhuru Peak, the night time temperatures can range between 0°F to -15F (-18°C to -26°C). This make Kilimanjaro weather very dynamic and you should always be prepared for wet days and cold nights.
Weather conditions near the base of the mountain tend to be tropical to semi-temperate and are relatively stable all year round. The lower plains are hot and dry with average temperatures of around 90 degrees Fahrenheit. As one heads away from the lower plains towards the rain forest, conditions become increasingly warm and humid.
Mount Kilimanjaro is divided into five distinct zones: cultivated farmlands on the lowest levels, next is the rainforest zone, followed by heath and moorland with alpine vegetation, and just before the barren, snowy summit is lunar-like desert. The climate and animal life changes from zone to zone.
The long rains typically occur from March to May and it is at this time when visibility is reduced and the mountain can become slippery. The shorter rains occur during November and December while June through October is summer time and is most conducive for climbing the mountain. However, weather on the mountain can change at any time and you should be prepared for rain - even during the dry season. One of the benefits of attempting to climb the mountain during the April and May is that there are fewer climbers -in fact you may have the summit all to yourself.