Firefighters were called to the eighth fire in Centre Vale park since the beginning of June last night (Tuesday).
Appliances from Todmorden and Mytholmroyd were called to the park at 9.30pm, following reports of a small fire in the changing rooms near the Lucky Dog statue.
It is thought the fire was started deliberately and is the latest incident in a string of nuisance fires in the park.
Watch commander Geoff Shaw, of Todmorden Fire Station, said: “I would urge all members of the public to remain vigilant.
“They have all been small fires, but small fires can get bigger. It’s going to get to the stage where we could turn out to the bandstand fully involved in fire.”
Crews used a high pressure hose reel to put the fire out and left at around 10.30pm