The Köppen climate found in Beijing, China, is Dwa, a monsoon-influenced humid continental climate with dry winters.
The first letter, D, denotes a continental climate with cold winters. The w means winter is the dry season, while a indicates a hot summer. Beijing’s climate reflects the seasonal reversal of East Asian monsoon winds: humid air brings most of the city’s rainfall in summer, while winter is cold, windy, and very dry.
The Siberian High is especially important in winter, sending cold continental air southward. In summer, the East Asian monsoon brings warmer, moisture-laden air from the south and southeast. Roughly three-quarters of Beijing’s annual precipitation falls between June and August, making the seasonal contrast unusually strong.
Beijing is sometimes described as bordering a BSk cold semi-arid climate, particularly in discussions of regional conditions and urban boundaries. That can create confusion, but the standard city classification used in the question is Dwa. Spring can also bring dust storms from the Mongolian steppe, while January averages about −2.7°C and July about 27.2°C.