The climate of Usagara is cold and damp. It has two distinct varieties, the upper regions being salubrious, as the lower are unwholesome. In the sub-ranges heavy exhalations are emitted by the decayed vegetation, the nights are raw, the mornings chilly and misty, and the days are bright and hot. In the higher levels, near the sources of the Mukondokwa River, the climate suggests the idea of the Mahabaleshwar and the Neilgherry Hills in Western India. Compared with Uzaramo or Unyamwezi, these mountains are a sanatorium, and should Europeans ever settle in Eastern Africa as merchants or missionaries, here they might reside until acclimatised for the interior. The east wind, a local deflection of the south-east trade, laden with the moisture of the Atlantic and the Indian Oceans, and collecting the evaporation of the valley, impinges upon the seaward slope, where, ascending, and relieved from atmospheric pressure, it is condensed by a colder temperature; hence the frequent precipitations of heavy rain, and the banks and sheets of morning-cloud which veil the tree-clad peaks of the highest gradients. As the sun waxes hot, the atmosphere acquires a greater capacity for carrying water; and the results are a milky mist in the basins, and in the upper hills a wonderful clearness broken only by the thin cirri of the higher atmosphere. After sunset, again, the gradual cooling of the air causes the deposit of a copious dew, which renders the nights peculiarly pleasant to a European. The diurnal sea-breeze, felt in the slope, is unknown in the counterslope of the mountains, where, indeed, the climate is much inferior to that of the central and eastern heights. As in the Sawalik Hills, and the sub-ranges of the Himalayas, the sun is burning hot during the dry season, and in the rains there is either a storm of thunder and lightning, wind and rain, or a stillness deep and depressing, with occasional gusts whose distinct moaning shows the highly electrical state of the atmosphere. The Masika, here commencing in early January, lasts three months, when the normal easterly winds shift to the north and the north-west. The Vuli, confined to the eastern slopes, occurs in August, and, as on the plains, frequent showers fall between the vernal and the autumnal rains.