The Lake Nyasa Climatic Region described in this study is composed of the Livingstone, Kipengere, Mbeya, and Umalila ranges, Mporoto Ridge, Mt. Rungwe, and the Kitulo Plateau. The region is located on the rift escarpment at the northeast end of Lake Nyasa. Floristic studies in the area reveal many unique plants, some of which are endemic to this region. The climate of the region is governed by altitude and its proximity to Lake Nyasa, which results in generation of high convectional rainfall. The high rainfall and diversity of habitats interacting with soils and other environmental factors in the area are responsible for the richness of the flora, and the current identifications of vascular plant taxa have yielded a total of 170 families, 733 genera, and 1736 species. The Lake Nyasa Climatic Region, therefore, has nearly 14% of the estimated total of 12,500 vascular plant species in all of Tropical East Africa.