DC sends another reference: Zech, M. (2006). Evidence for Late Pleistocene climate changes from buried soils on the southern slopes of Mt. Kilimanjaro, Tanzania. Palaeogeography, Palaeoclimatology, Palaeoecology 242(3-4): 303-312.

Abstract: The distribution of the altitudinal vegetation zones on the slopes of Mt. Kilimanjaro is well-known. But no reliable data are available about the vegetation shifts during the Quaternary. Here I present palaeopedological results (elemental, biomarker, stable isotope and radiocarbon analyses), indicating that the frequently occurring buried black A horizons in the montane forest belt are developed under ericaceous vegetation. Since Erica species are not abundant at this altitude nowadays but are characteristic for the sub-alpine zone, the palaeosols reflect palaeoclimatically driven fluctuations and changes of the vegetation zones on Mt. Kilimanjaro. The downhill descent of the ericaceous belt coincided with cold and dry periods like the Late Glacial and the Last Glacial Maximum. Older palaeosols document that such events also took place during the Marine Isotope Stages 3 and 4.

David Campbell brings to our attention the work of Rohr, P.C. and Killingtveit, Å. (2003). Rainfall distribution on the slopes of Mt Kilimanjaro. Hydrological Sciences Journal 48(1): 65-77. Wouldn't it be excellent if they would move around to the northern slopes?

Abstract Observations from new precipitation gauges on the southern slopes of Mt Kilimanjaro are used together with observations from the regular network to establish an elevation function for the precipitation on the southern hillside of Mt Kilimanjaro. A third-order polynomial function is found to best describe the distribution of precipitation with elevation for the lower half of the hillside. On the upper half of the hillside, an exponential function is found to best describe the precipitation distribution with elevation. The availability and quality of the precipitation records is often a limiting factor for analyses and may influence the results. A reference precipitation series for the area is established through thorough screening and quality checks of the available data. The elevation function is compared with an isohyetal map for the area. The findings indicate that the maximum precipitation on the southern hillside of Mt Kilimanjaro takes place at about 2200 m a.s.l. which is 400–500 m higher than assumed previously.