What is sun?
The Sun is just like any other star which gets its energy by nuclear fusion of hydrogen nuclei into helium. The surface of the sun is actually its coolest layer while the core is the hottest.
What is lightning?
Lightning is an atmospheric electric discharge caused by thunderstorms or dust storms. Lightning causes strong electric field which ionizes the air around and separates the air molecules into positive ions and electrons. When this ionised air comes into contact with the ground from the cloud, high temperature current flows in the form of lightening stroke. This lightning stroke establishes a temperature that is hotter than the sun.
The temperature is nothing but the energy that comes from the number of particles which are millions in number. This energy lasts only for a short time like a microsecond, but the rate at which it scatters can be very large.
How hot is lightning bolt?
A bolt of lightning can reach a temperature of 53,540 degree Fahrenheit as compared to just 10,340 degree Fahrenheit of the sun!