Tall objects such as trees and skyscrapers are more likely than the surrounding ground to produce one of the connecting sparks and so are more likely to be struck by lightning. Mountains also make good targets. However, this does not always mean tall objects will be struck.
The lightning discharge heats the air rapidly and causes it to expand. The temperature of the air in the lightning channel may reach as high as 50,000 degrees Fahrenheit, 5 times hotter than the surface of the sun. Immediately after the flash, the air cools and contracts quickly.