In general the weather patterns around Kilimanjaro vary depending on when the long and short rains fall. The long rains normally last from the end of March through to early June. Torrential downpours in the forested slopes fall as snow at higher levels. The short rainy season tends to start towards the end of October and the weather on Kilimanjaro becomes more unstable again.

However, because of its size, Kilimanjaro can generate its own weather and, as in a lot of East Africa, weather patterns are becoming far less predictable, with cloud and rain possible at all times of the year. Whenever you go you should be prepared for extreme conditions. The weather will also vary dramatically depending upon the time of day and how far up the climb you are, since all of the routes cross a number of very different ecological zones, each with its own weather. In general the higher you climb the less the annual precipitation and the drier it gets.

August and September is the peak climbing season on Kilimanjaro. The weather is good with many clear days and warmer than in June/July. The period around Christmas and New Year is the second busiest climbing season on Kilimanjaro. Traffic is extremely high despite there still being a good chance of rainfall and thick cloud.

At the start you will be walking through thick forest which can receive 2 metres of rain in a year. Even at this level, if the sky is clear, the nights can produce low temperatures. Higher up the mountain, temperature extremes tend to be far more drastic and the variation between day and night temperatures becomes more and more apparent. Above 4000 metres evenings tend to be frosty and cold, whilst scorching daytime temperatures are typical of what one would expect from a country bordering the equator.

At around 3000 metres the forest gives way to semi-alpine heath, characterised by heath-like vegetation and flowers. At 4000 metres you reach alpine desert which receives little water and correspondingly little vegetation exists. The temperature can vary from over 100 degrees Fahrenheit during the day to below freezing at night.

Above 5000 metres the arctic zone is characterized by ice and rock with virtually no plant or animal life. The air is icy and dry and temperatures fall to well below zero. Nights are extremely cold and the sun extremely powerful during the day. The air is thin with the oxygen level being half that of sea level.  The temperatures during summit night can drop to -20°C (-5°F) and with wind chill may feel as low as -40°.

Most climbers end up sleeping in all their clothes, including hats and gloves on the last night before heading for the summit.

On summit day you should carry or wear shorts and a T-shirt beneath your cold weather gear so you don’t overheat, towards the end of the day, on the way down.