Hot temperatures and dry conditions have increased the fire risk in northern Victoria this week, the Bureau of Meteorology warns.

Senior forecaster Michael Efron says warm to warm conditions are expected Wednesday before a cold front passes through.

He says people need to be aware of changing conditions.

An extreme fire danger rating is forecast for the Mallee district on Wednesday, with Wimmera and parts of central Victoria rated as high.

Mr Efron said temperatures would be in the low to mid 30s with thunderstorms.

With minimal rain forecast, lightning could spark hundreds of fires, he said.

Lightning causes fire in national park

Lightning is believed to have sparked five fires in the state’s northeast on Sunday afternoon, including a bushfire in Chiltern-Mount Pilot National Park, about 20 kilometers east of Wangaratta.

CFA District 23 Commander Daryl Owen said more than a dozen appliances, including two planes, were called to Beechworth-Wangaratta Road in Everton Upper to tackle the fire as part of a joint effort of CFA and Forest Fire Management.

He added that although the 5-hectare fire was minor, it occurred in “fairly inaccessible terrain” and water bombs had to be used to attack the perimeter of the fire.

Commander Owen said there was some rain in the north-east of the state on Sunday morning.

“But from lunchtime onwards, the humidity decreased, the sun came out and temperatures rose with the wind,” he explained.

“This saw lightning flashing through some trees and grasslands in the bush.”

Fire danger period begins for Loddon-Mallee

With an extreme fire risk predicted for the Mallee, CFA Deputy Fire Chief for District 20 Mick Sporton has urged residents to prepare over the coming days as the environment ‘rapidly burns out’ .

“The grasslands are about 80 percent (dry)… and from midnight last night the fire danger period came into effect,” Mr Sporton said.

“The forest itself is extremely dry. With the weather forecast this week, we will be on high alert.”

He said the focus in recent days had been on preparing volunteers and strike teams in case they were needed, amid hot and windy weather ahead.

“We always emphasize having a plan, but never is it more important than now,” Mr. Sporton said.

He advises people to have enough clothes and food packed, as well as somewhere they can go if they need to leave quickly.

“Learn about your neighbors,” Mr. Sporton said.

The fire danger period begins on Monday for the local government areas of Buloke, Campaspe, Gannawarra, Loddon, Northern Grampians and Swan Hill.