Los Angeles County Fire officials responded to Encanto Parkway, near the Vulcan Materials Company on Fish Canyon Road, around 12:45 p.m.
One of the fires was estimated at 0.25 acres and burned near the area where the Madre Fire erupted in September. All three fires were quickly contained.
No injuries were reported.
Azusa police urged drivers to stay clear of Encanto Parkway for emergency vehicles.
The cause of the blaze remains under investigation.