Annual temperatures at Trou au Natron fluctuate between , with a daily temperature variation of ; this is less than in the lowlands. At higher altitudes frost can be expected. Precipitation amounts to at Trou au Natron. Most of it falls as frontal precipitation during summer, and it is more copious than in the lowlands; the Tibesti mountains are the sources for wadis. Other, more indirect estimates yield precipitation of per year at Toussidé.