Cusco has a subtropical highland climate (Köppen Cwb). Its climate is generally dry and temperate, with two defined seasons. The dry season lasts from April through October, with abundant sunshine, and occasional nighttime freezes: July is the coolest month with an average of 9.6 °C (49.3 °F). The wet season lasts from November to March, with night frost less common: November averages 13.4 °C (56.1 °F). Although frost and hail are common, snow is virtually unheard of. The last snowfall was recorded in June 1911.
Cusco was found in 2006 to be the spot on Earth with the highest ultraviolet light level.