How Hot Is Lightning?
The air within a lightning strike can heat up to 54,000 degrees Fehrenheit. To put that in perspective that is nearly 6 times hotter than the surface of the sun.(1)
The average flash will light a 100 watt bulb for more than 3 months.(2)
Lightning heats the air so rapidly that the air molecules expand violently creating a noise, called Thunder.
(1) The Handy Weather Answer Book. Lyons, Walter A. Accord Publishing, 1997
Pictures courtesy of the NOAA photo library: http://www.photolib.noaa.gov/search.html