Why does China in general have a hotter summer and colder winter compared to the same other latitude areas?
China, being big and having only one coastline, has what is called a continental climate. Those climates are characterised by extremes of temperatures. Coastal areas (in in China) have what is called a maritime climate. Those climates are characterised by reduced extremes and moderate temperatures because of the relative temperature stability of large bodies of water like the ocean. Obviously there are variations caused by the large range of latitude from Hainan island to Heilongjiang.
continental setting combined with an unfortunately high range of mountains on its equatorial side (which block moist and warm air flow from the south, mostly). The land heats up in the summer (no nearby ocean to moderate and lack of clouds to prevent heating because dryer) and cools down more in winter (no ocean nearby to moderate and lack of clouds to moderate because still dryer). Same reason central Canada is like that, more or less.
Mountain ranges, including the highest on Earth, the Himalayas. Ever wonder why there are deserts on the east side of north south mountain ranges in North and the South Carolina America? It raise and snows on the west side, but not on the east side.
It's is gods absence that drives the weather Into extremes. Our weather is getting worse Since dems retook the house.