Long grass around Wairarapa, including that growing on the roadside, is increasingly a fire trap, a rural fire officer has warned.
A mild December with plenty of rainfall has boosted grass growth around the region, according to Travis Howell, rural fire district communication and education officer.
"What could be the biggest threat in the next couple of weeks is roadside fires."
Grass had built up along some rural roads to heights in some cases above the fenceline, Mr Howell said.
While the grass closest to the roads was usually mowed by district councils, long grass across the ditch closer to boundary fences could also catch fire.
This can happen with a cigarette flicked out a window, or with other ignition sources like "deposits that can come from the exhausts of diesel vehicles", Mr Howell said.
"But cigarettes are the big one."
A ditch full of water will not prevent fire spreading, Mr Howell warns, as fire will travel through the top of the grass and through a boundary fence on to a farmer's property.
The long grass can be either sprayed, mown or grazed by the farmer.
"Some farmers often fence and graze it," Mr Howell said.
"I try and promote that people get out and reduce that risk along the roads."
The build-up of long grass, roadside and otherwise, was a fire hazard that had eased somewhat after three days of rain from December 30 to January 1, Mr Howell said.
However, a forecast northwesterly wind this week will dry out the grass - now even longer - all over again.
"Surface fuels like that grass dry out extremely quickly," Mr Howell said.
Wairarapa is still in an open fire season but Mr Howell said those lighting outdoor fires should take precautions.
"Have a fire break and a supply of water handy," he said.
"If you have some questions phone us and we can help you, or even come out."