The first was on Friday, July 3, at 12.30am in Station Road at Keadby.
Involved was a plastic bench in the park.
Crews extinguished the fire using one hose reel. The incident was left with the police.
At 12.21pm the same day, firefighters were called to Wharf Road in Ealand where a quantity of waste timber was on fire.
One hose reel, one main jet and one hay drag were used to deal with the incident.