I have two layovers in China on the way to Thailand. Will I need a visa?

depart Toronto....
arrive - 7:20pm Tue Feb 20 Shanghai (PVG)
20h 50m Layover in Shanghai, China (PVG) Change of airport required
depart - 4:10pm Wed Feb 21 Shanghai (SHA)
arrive - Wed Feb 21 7:50pm Kunming (KMG)
20h 35m Layover in Kunming, China (KMG)
depart - 4:25pm Thu Feb 22 Kunming (KMG)
arrive - Chiang Mai Thu Feb 22