Beijing has a monsoon-influenced humid continental climate (Köppen: Dwa), characterized by hot, humid summers due to the East Asian monsoon, and brief but cold, dry winters that reflect the influence of the vast Siberian anticyclone.[82] Spring can bear witness to sandstorms blowing in from the Gobi Desert across the Mongolian steppe, accompanied by rapidly warming, but generally dry, conditions. Autumn, similar to spring, is a season of transition and minimal precipitation. The monthly daily average temperature in January is −2.9 °C (26.8 °F), while in July it is 26.9 °C (80.4 °F). Precipitation averages around 570 mm (22 in) annually, with close to three-quarters of that total falling from June to August. With monthly percent possible sunshine ranging from 47% in July to 65% in January and February, the city receives 2,671 hours of bright sunshine annually. Extremes since 1951 have ranged from −27.4 °C (−17.3 °F) on 22 February 1966 to 41.9 °C (107.4 °F) on 24 July 1999 (unofficial record of 42.6 °C (108.7 °F) was set on 15 June 1942).[83][84]