Temperatures of up to 45 degrees, low humidity and winds between 30 and 50km/h are forecasted.

A change that might bring lightning are expected on Sunday and into Monday.

Forest Fire Management Victoria Hume deputy chief fire officer Aaron Kennedy said it was crucial those in national parks and around waterways don't add to the fire risk.

"We know that tens of thousands of people will be visiting our camping areas across the region this long weekend, and we know that there is a real potential for bushfires to appear across the landscape," he said.

"So we're asking people to play their part, and ensure, particularly around campfire safety, to do the right thing."

Since November last year, FFMVic crews have recorded 160 unattended campfires, some starting small fires.

"We know that a single ember from one of those unattended campfires can spark a major bushfire," Mr Kennedy said.

"We've got crews rostered on, ready to respond this weekend.

"The entire landscape has dried out, particularly in our forested areas as well, so any fires that ignite ... will be very difficult to contain.

"Fully extinguish your campfires with water, making sure it's fully cool to touch, and never leave a campfire unattended."

CFA Hume region assistant chief fire officer Paul King said it was crucial people were aware of the conditions and fire danger ratings.

"Particularly Monday is going to be really difficult fire danger day," he said.

"That's not to say Sunday won't be, but as the change comes through Monday, it is going to be a particularly difficult fire danger day.

"That's on the back of it this real heating up period that starts today.

"Staying informed about what's happening in the area that you're planning to be in for the weekend is really important. The Vic Emergency app and the Fires Near Me app are great resources that travel with you.

"If you're going through an area of high risk, you really should reconsider because it's not the place to be on a severe fire weather day.

"There are lots of fantastic places for people to travel to in the northeast of Victoria. But just be aware."

NSW Rural Fire Service southern border team district manager Pat Westwood said four to five days of 40-and-above temperatures was concerning.

"In particular, we're concerned about the river campsite areas. And we're also concerned about some of our open grassland areas that have got quite a large amount of fuel this year after the rain we've had," he said.

"A year ago tomorrow, we set the Green Valley fire to 'out'. And that started by a lightning strike. And this year, we're going to see four or five days of weather that could easily start fires of that significance.

"So we're asking people to do the right thing. It's probably not the best to have a fire at all in that 40 degree temperature. There may be total fire bans in place.

"I'm most concerned about Sunday and Monday nights; I think the risk of lightning hasn't been identified yet ... but there is a possibility that we could see thunderstorm activity."

Wodonga Detective Sergeant Graeme Simpfendorfer said police would be patrolling this weekend.

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"We expect a high number of people to visit us in the North East, and that is welcomed, come and visit and experience everything we've got to offer. But be safe," he said.

"If you are up here enjoying the conditions and the environment, in and around the water, be safe and look after your mates.

"And if you're drinking, don't go in the water.

"Don't be reckless in your behaviour."