The matter was now in the hands of police, Mr Rackham said.
On December 13 Arataki School also became a target.
Mount Maunganui Fire Station Officer Paul van Kol said the brigade was called to Arataki School about 1.30am that day, and discovered a smouldering deck under the eves of one of the buildings.
"It appears someone has pushed a bit of paper through the decking slates and lit it.
"While it was a small fire and only resulted in minor damage, a minor arson attack can easily turn into a major fire causing tens of thousands of dollars of damage," he said.
Mr Rackham said the latest arson attempt at Opotiki School on Sunday night involved someone lighting a fire on the decking of a facility at the school.
The investigation was still in its early stages, and he would not make any further comment until his inquiries were completed, he said.
"It's very troubling that we've already had three school fires this summer. Schools often have a spate of smallish fires on their grounds, such as rubbish bin fires, before a major arson attack."
Mr Rackham urged school officials and nearby residents to remain vigilant and report any fires or vandalism to police and the fire service immediately.
"Most school fires are started using rubbish, a bit of paper, clothing or other easy-to-burn items already left on school grounds.
"We recommend all fixed bins and wheelie bins be at least 5m away from all buildings, and lock and secure bins so they can't be moved up against structures."
Mr Rackham said there had been up to 40 suspicious or deliberately lit fires at schools in the Bay of Plenty/Waikato region since 2012, estimated to have cost $20.7 million.