Fire crews and drones will patrol the Waikari fireground overnight to identify any further hotspots

Firefighters have spent today tackling deep-seated hotspots - the fire's now burnt 327 hectares with a perimeter of 8.6 kilometres.

Incident Commander Des Irving says a drone will carry out thermal imaging to find hotspots that three fire crews will tackle tomorrow.

He says last night's rain helped cool the fire ground but hasn't changed the underlying high fire danger.