Two vacant rowhomes caught fire just after 4 a.m. on the 2200 block of North 7th Street in North Philadelphia.
Flames could be seen shooting from the roof of one of the homes.
A salt truck was called in as sub-zero temperatures caused icy conditions on the road as water was being pumped on the fire.
There were no reports of any injuries.
In Tacony, smoke and flames damaged a rowhome.
The fire started just after 2 a.m. on the 4700 block of Longshore Avenue.
Authorities said the homeowner was able to escape safely.