Around 400 metres of moorland in the Pule Hill and Intake Head area is alight and West Yorkshire Fire and Rescue Service are at the scene.
They said: "400m flame front. Beaters and blowers in use. Specialist wildfire vehicle in attendance. Please avoid the area as we tackle this incident."
Marsden Moor, near Holmfirth, has been affected by numerous wildfires in recent years, most of which started during warm weather - though today's temperatures barely topped 13 degrees.
The use of barbecues has been blamed for starting many of the fires. On March 2, three fires caused by disposable barbecues had to be dealt with.
During the April 2021 heatwave a major blaze broke out on the moor.
Earlier this year an artist was jailed for starting the fire by experimenting with a device to launch fireworks.
It is thought that the peat soil damaged in the wildfire could take thousands of years to recover.