PHOTOS: 'Firenado' in San Diego County

A 'firenado' spins above houses in San Diego County on May 15, 2014, as several wildfires burned across the county.

The phenomena happens when heated air rises and twists with the spinning of the Earth, according to ABC7 meteorologist Dallas Raines.

So far, the San Diego County fires have charred more than 15 square miles and caused more than $20 million in damage, burning at least eight houses, an apartment complex and two businesses.