The Marlborough District Council is warning people to be careful on the Wither Hills.
Blenheim deputy principal rural fire officer John Foley said the area was already very dry and the fire risk was increasing.
"If anyone sees anything suspicious in this area, we need them to report it straight away. Don't hesitate to contact the emergency services."
The council was erecting signs at the main entrances to the Wither Hills Farm Park warning people not walk in the area during the hottest part of the day, and to carry a cellphone when they are out walking.
Park users are being reminded there are emergency location signs along all the tracks, at junctions and lookout points throughout the farm park and the mountainbike park. Each sign has the name of the track and the GPS co-ordinates to help anyone caught in a fire to notify emergency services.
Once a blaze ignited, the situation quickly became serious, Mr Foley said. "You cannot out-run a fire, particularly when the wind comes up."
- The Marlborough Express