What's the weather like in Chengde from June to September?

Chengde, located in the hinterland of Yanshan Mountain, is 40? 1 1'-42? 40', east longitude 1 15? 54'- 1 19? 15'。 It belongs to the transition zone from sub-temperate zone to sub-frigid zone, with semi-humid and semi-arid continental monsoon climate, four distinct seasons, abundant sunshine and large temperature difference between day and night. The average annual temperature is 8.9? C the annual average frost-free period is 160 days. Summer is warm and cool, winter is not too cold, and rainfall is moderate.