It is located on the south-eastern side of an oasis which supports the town's population.

A sebkha (salt lake) lies further to the northwest, while the plateau of Tademaït rises to the southeast.

Timimoun has a hot desert climate (Köppen climate classification BWh), with extremely hot summers and warm winters, with minimal rainfall throughout the year.

Timimoun lies on the N51 national highway, a road which runs roughly west to east from the N6 (connecting to Béchar in the north and Adrar in the south) to the N1 (connecting from Ghardaïa in the north to In Salah and Tamanrasset in the south).

Regional roads also lead south to Aougrout and Deldoul communes, and north to Tinerkouk, Ksar Kaddour and Ouled Said.