Huailai County is located in the eastern part of Zhangjiakou prefecture, with latitude ranging from 40° 04′ to 40° 35′ N and longitude 115° 16′ to 115° 58′ E. It contains the upper reaches of the Yongding River and borders Beijing Municipality. It is 87 kilometres (54 mi) east-southeast of the urban area of Zhangjiakou and 120 kilometres (75 mi) west-northwest of Beijing city proper.
Huailai County has a monsoon-influenced, continentalsemi-arid climate (KöppenBSk), with cold, dry, and windy winters and hot, humid summers, with temperatures slightly warmer than Zhangjiakou due to the more southerly location but still significantly cooler than in Beijing due to the high elevation. The monthly 24-hour average temperature ranges from −7.0 °C (19.4 °F) in January to 24.8 °C (76.6 °F) in July, and the annual mean is 10.01 °C (50.0 °F). A majority of the annual rainfall occurs in July and August alone. With monthly percent possible sunshine ranging from 60% in July to 73% in January and February, sunshine is abundant year-round, totalling about 3,030 hours annually.
Climate data for Huailai County, elevation 571 m (1,873 ft), (1991–2020 normals, extremes 1971-present)
^2011年统计用区划代码和城乡划分代码:怀来县 (in Chinese). National Bureau of Statistics of the People's Republic of China. Archived from the original on April 7, 2013. Retrieved 2013-02-24.