When considering an ascent of Kilimanjaro, we frequently receive enquiries about what climbers should expect in terms of temperatures, precipitation and Kilimanjaro weather patterns. While this information is of course useful, it tells only a very small part of the story in terms of informing a climber as regards how they should prepare.
Kilimanjaro Weather is not Enough to Inform Clothing Choices
Snow Forecast forecasts Kilimanjaro’s weather over the next five days and advises current temperatures at Kilimanjaro’s assault launch camps (though please bear in mind that the large characters denoting current temperature represent the temperature at the airport, not on the mountain!). So while these are of interest, we wish to caution strongly against climbers being overly reassured by these figures. It is a mistake to conclude that these temperatures look much friendlier than say, a Canadian winter, or a skiing holiday, as these temperatures do not offer an effective equivalent skin extremities temperature estimate once one has factored-
The Combined Effect of Weather and Altitude
The most underestimated factor that is responsible for how a climber copes with Kilimanjaro weather is altitude. Until one has experienced cold at altitude, and without asking a biologist to assist us with a complex description of how the body responds to oxygen-
Most readers will already understand very well that at altitude the proportional composition of the air is pretty much identical to that at sea level, with oxygen making up a little under 20% of all inspired air. However, as one ascends there is effectively a smaller column of air pressing down upon the climber, between the outer reaches of the earth’s atmosphere and the climber’s location. As the weight of the air above the climber reduces with the increase in altitude, the force that binds air molecules together is correspondingly lessened, so the air becomes less rich, less dense. Or in common terms, we say that the air pressure becomes lower.
Depending on where one lives, we can describe normal sea level air pressure as being 1 atmosphere, or 1,000 mbar. By the time one reaches the elevation of Kilimanjaro’s summit (5,895m) the air pressure will usually have dropped to around 480 –
As an aside, it may be of interest to climbers to know that Diamox (acetazolamide) achieves this increased respiration rate synthetically by acidifying the blood, thereby effectively asking the chemo-receptors in the person’s neck to acknowledge that a message should be sent to the hypothalamus to tell the autonomic respiratory system to breath more frequently so as to flush out excessive accumulated CO2 (in order to achieve the central objective of inspiring more O2). Climbers should also bear in mind, however, that where a climber understands what is required, it is not actually necessary to artificially induce this increased respiration rate, as the climber can themselves voluntarily increase their breathing rate through practiced (non-
The Demand for Oxygen in Cold Climates
Thermoregulation of the body in mammals is of course very resource-
The Body's Response to Low Atmospheric Oxygen Levels
Predictably, the body’s response to these demands are principally two-
Climbers should please understand then, that while the minus 8 degrees Centigrade that typically can be expected at the summit may not sound very daunting, when combined with the effects of low oxygen and windchill, the level of care with which climbers should plan their clothing strategy, is a matter of very great importance that we are very happy to advise with via email correspondence.
Seasonal Kilimanjaro Weather Patterns
Broadly speaking, while we are happy to arrange climbs on Kilimanjaro on any given day of the year, most climbers tend to avoid April, May and November as these represent the greater part of the two annual rainy seasons. Climbing during rainy months offers advantages in terms of lower crowds and a more beautiful summit that is often enveloped in snow, however, lower elevations are more often overcast, with photographic opportunities sometimes being compromised, and a greater likelihood of being rained on.