Xian boats many schools. There are a lot of foreigners there. Besides official schools, there are many private schools and laguage training schools. You can find a large number of students there. In my opinion, Xian would be better. This city once was a famous ancient capital of many dynasties. I bet you would love it deeply.

both Wuhan and Xi'an are very hot in summer, but Wuhan is much hotter. however in winter, there are intensive heat in Xi'an while not in Wuhan