A fire that turned hundreds of cars into ash at a wrecking yard in Revesby on Saturday is almost contained, according to NSW Fire and Rescue, with one man suffering minor burns and three men treated for smoke inhalation.

The service has scaled back the 100 firefighters and 20 fire trucks that had been battling to prevent the fire on Mavis Street from spreading to nearby houses.

Eastbound lanes have reopened on Canterbury Road and diversions onto The River Road have been lifted. Traffic is slowly returning to normal.

Warm, windy and clear weather has assisted a series of fires across Sydney with emergency services responding to blazes in Castle Cove, Mulgrave, Llandilo, Revesby, Terrey Hills and the Hunter Valley.  

Firefighters are also at the scene of a five-hectare grass fire on Byron Street in Mt Druitt, now contained with no properties threatened.

In the Hunter region, an emergency warning is place for a large bushfire burning in the area of Racecourse Road at Cessnock has been downgraded to "watch and act".

The fire was burning on several fronts and properties have been impacted, says the RFS. 

The RFS has also issued a "watch and act" for a bush fire burning near the Pacific Highway at Balickera, north of the Grahamstown Dam and a bush fire burning at King Creek near Wauchope. Both are described as "out of control".

NSW Fire and Rescue Superintendent Adam Dewberry said the Revesby car yard had been "well-alight" and that winds had pushed the blaze into residential streets. Homes on Jellicoe Street and Gallipoli Street were evacuated.

Bankstown-Lidcombe Hospital had been on standby to evacuate if the fire reached adjoining buildings. 

The men suffering smoke inhalation from the Revesby fire were treated at the hospital, and have all been discharged. Another man suffering minor burns to his arm is in a stable condition at Liverpool hospital, and may be transferred to the burns unit at Concord Hospital.

Emergency Services had received multiple calls reporting the fire, with billowing smoke visible from neighbouring suburbs.

An eight-hectare fire in a Castle Cove reserve on Deepwater Road on the lower North Shore has been extinguished. The residents of ten homes that had been evacuated in the surrounding area have been allowed to return, with no property damaged. Former prime minister Tony Abbott was one of several volunteer firefighters who helped extinguish the blaze. 

The first fire ban in NSW for the season has been in effect on the Far North Coast since this morning, in response to forecasts predicting warm weather and northwesterly winds of up to 60 kilometres per hour. A southerly change moving up the coast is expected to cool temperatures later tonight.

Rural Fire Services has listed the greater Sydney region as a 'very high' fire danger zone.

The past 36-hours have delivered a sobering portent of the fire risk in in coming summer months.

On Friday a bushfire in Llandilo and Cranbrook burned ferociously for four hours, causing police officers to evacuate homes, two schools and a nursing home. The Rural Fire Service reported damage to a number of properties on streets bordering the fire.

Eventually, 200 firefighters from the Rural Fire Service and Fire and Rescue NSW were able to get the blaze under control at 6pm. On Saturday a 16-year-old boy was arrested at Penrith Railway Station and later charged with intentionally causing a fire and recklessness. 

Less than five kilometres away from the Llandilo fire, 2000 bails of hay are alight at a farm supplies property in Mulgrave. 

Superintendent Adam Dewberry said the cause of the fire was not yet known. 

"With extreme fires it is possible for spotting to occur that far ahead. However, due to exothermic reactions within hay bails, they are also known to spontaneously ignite," Mr Dewberry said. 

The fire is encroaching on the T1 Western railway line to Richmond. As track work is occurring on this line over the weekend the fire has not impacted existing public transport arrangements. 

Currently, fire crews are using a remotely operated fire fighting engine to pull apart the burning bails of hay and soak them in foam and water. 

Due to further forecasts of warm and windy weather, Mr Dewberry said he expects fire crews will be present at the Mulgrave fire for the next few days. "It will be very smoky," he said.

Mohammed Nabi of the Bureau of Meteorology said rain is not expected in Sydney until Wednesday. 

"Currently there are winds southwesterly winds in Sydney of 30 to 45 kilometres per hour and there will be clear conditions until the evening. Wednesday is the next day showers are expected to come through," Mr Nabi said. 

A 490 hectare fire that started yesterday continues to burn at Callala Bay near Jervis Bay. 

A number of bushfires have sparked in to the Hunter Region threatening road access and property. Inspector Ben Shepherd of the Rural Fire Service said an out of control bushfire on Racecourse Road is expected to cross the railway line. Property protection action is underway. Another out of control bushfire north of Raymond Terrace, originating on Lone Pine Road, is expected to cross the Pacific Highway.