Firefighters have been given hope by this week's weather forecast which predicts heavy downpours in New South Wales and rain in Victoria - although there will be no relief for Kangaroo Island.

The Bureau of Meteorology published a map which shows rain forecast for almost the whole of NSW in the next seven days.

The map was re-tweeted by the state's Rural Fire Service with the caption: 'If this rainfall forecast comes to fruition then this will be all of our Christmas, birthday, engagement, anniversary, wedding and graduation presents rolled into one. Fingers crossed.'

The Bureau of Meteorology published a map (above) which shows rain forecast for the whole of NSW in the next seven days

The map was re-tweeted by the state's Rural Fire Service

On Monday pockets of the central and northern coasts will see rain.

The heavier downpours are due on Thursday when thunderstorms and showers are forecast for most of NSW and up to 25mm is expected to fall on parts of the south coast.

Sydney is expected to receive its most significant downpour in several months, with forecasts of 2-8mm on Thursday and 5-10mm on Friday.

However, forecasters warned that the rain could be so heavy it may cause landslides.

BOM meteorologist Gabrielle Woodhouse said: 'We are looking at a couple of days in a row of some showers and thunderstorms, some of which may produce significant accumulation over those couple of days.

'It will be quite welcome but there are some extra dangers and risks associated with it as the landscape is quite vulnerable with the fire damage.

'We've lost a lot of vegetations and there is the risk of landslips.'

This weather map shows how rain is forecast to fall over much of Australia in the coming days

A Rural Fire Service firefighter Trevor Stewart views a flank of a fire on January 11, 2020 in Tumburumba

NSW Rural Fire Service spokesman Anthony Bradstreet said fire conditions are expected to ease on Monday and throughout the week with rain on the horizon.

'We would love rain everywhere,' he said on Monday.

'Hopefully we will receive some good rainfall in fire affected areas.'

Mr Bradstreet warned thunderstorms could create the risk of falling trees and landslips.

Crews will take advantage of the easing conditions to establish and strengthen containment lines on some 40 bushfires which are not yet contained, he added.

He said rain was welcome but it would not be enough to completely put out all the fires.

'Looking ahead, there still is plenty of bush to burn and a lot of summer to go,' he said in a warning that the fire season was far from over.

The RFS said 111 fires were still burning across the state on Sunday night and many will take some time to fully contain.

Firefighters on Sunday brought under control one of the county's most damaging blazes - the Gospers Mountain fire, which has burned for two-and-a-half months northwest of Sydney.

'After lightning started the fire on October 26, it has burnt through more than 512,000 hectares across the Lithgow, Hawkesbury, Hunter Valley, Cudgegong, Blue Mountains and Central Coast local government areas,' the Hawkesbury RFS said on Facebook.

'It is important to remember not to be complacent as there are still a few months of the bushfire season to go with some bushland that still has not been burnt.'

Rain is also set to some bring relief to Victoria this week - but not enough to put out 19 fires.

Fires at Abbeyard in the high country and at Timboon in East Gippsland were both at emergency alerts early on Monday morning, but by 9am both had been downgraded.

The Dunn Road fire on January 10, 2020 in Mount Adrah, near Wagga Wagga in NSW

A car makes its way through thick fog mixed with bushfire smoke in the Ruined Castle area of the Blue Mountains on January 11

Milder conditions are expected to last throughout the week, with rain developing in the state's east on Wednesday and extending at least until Saturday.

Despite the respite, temperatures will hover about 30C and winds are still gusting, meaning the danger lingers and the fires show no sign of relenting.

'These fires aren't out and they're not going to be out until they out themselves out or we finish with a really big rain event,' Premier Daniel Andrews told KIIS FM on Monday.

'And the weather bureau's not telling us that's likely.'

There are 19 active fires across Victoria, including one at Corryong in the northeast which has merged with a fire in NSW at the weekend.

More than 1.3 million hectares has been burnt and 1,500 fire fighters remain on the job.

Poor and very poor air quality conditions due to the bushfires are forecast statewide, with smoke and haze in the east, northeast and central Victoria.

Meanwhile, fires will continue on Kangaroo Island where there is no rain forecast until Sunday.

Travel restrictions have been lifted, but Country Fire Service incident controller Ian Tanner said non-essential travel should be avoided.

'If you do need to come here to support relatives and friends, then it's OK to come,' he said.

'But if you don't need to come to Kangaroo Island at this point in time, then please give us a bit longer to get this sorted.'

The SA CFS said 30C weather and unfavourable conditions could lead to fire outbreaks and flare-ups on Monday.

'The CFS advises everyone on Kangaroo Island to be vigilant tomorrow as there may be an escalation in fire activity,' it said.

'Please monitor your local environment and be aware that fire conditions will be constantly changing throughout the day.'