The devastating NSW bushfire season which has claimed the lives of more than 20 people has been described as the "darkest summer" in the state's history.
The remark was made by NSW Emergency Services Minister David Elliott on Friday after three US firefighters died when their air tanker crashed while battling bushfires in southern NSW on Thursday.
Mr Elliott said he hoped the 2019-20 summer would never be repeated.
"I'm hoping we don't have a repeat next year, or the year after or for the next 10 years, but the reality is, we probably will," he told reporters on Friday.
NSW Rural Fire Service Commissioner Shane Fitzsimmons said the state would "forever be indebted" to the sacrifice the three men made.
Plane owner and operator Coulson Aviation on Friday confirmed captain Ian McBeth, 44, flight engineer Rick DeMorgan Jr, 43, and first officer Paul Clyde Hudson, 42, lost their lives in the crash.
Police and Australian Transport Safety Bureau investigators will on Friday begin collecting evidence and piecing together what caused the C130 water tanker to crash in Peak View.
Mr Fitzsimmons said very hot, dry and windy conditions on Thursday resulted in flare ups, fire spread and new fire ignitions, as well as suspected home losses.
Six firefighters battling the Clyde Mountain blaze on NSW's south coast were injured when their truck rolled near Moruya.
Three of them were kept in hospital on Thursday night for monitoring but none of the six firefighters' injuries are considered serious.
Mr Fitzsimmons said fire conditions had significantly eased overnight and into Friday with an easterly wind change causing decreased temperatures, an increase in humidity, and rainfall across parts of the state.
He urged people to remain alert, with thousands of kilometres of fires still burning that crews needed to contain before dry conditions return.
"We've still got to get through the end of January, we've still got to get through February which is one of our months of summer and we still have to get through the end of the statutory bushfire danger period which might be extended should the circumstances dictate beyond March," he said.
While the three-month weather outlook for NSW does include some rainfall, Mr Fitzsimmons said it wouldn't be above average.
"We're not getting any strong signals of above-average rainfall, drought-breaking rainfall or fire season-ending rainfall," he said.
More than 70 fires continue to burn across NSW, with 30 uncontained.
Premier Gladys Berejiklian on Friday announced a state memorial service will be held on February 23 in Sydney to recognise the lives lost, the sacrifices made and those who have been impacted by bushfires this season.
Australian Associated Press