Ouallene has a hot desert climate (Köppen climate classification BWh), with a really long, torrid summer and a brief, very warm winter, and averages just 17 millimetres (0.67 in) of rainfall per year. The excessively sunny, hot, dry climate is marked by very high temperatures and near-zero precipitation all year-long. During many months of the year, highs of 40° are common and from June to August, inclusively, highs are consistently hovering around 45° with lows rarely dropping below 30°.