Snow is forecast for the Upper Mountains and across large parts of the Central West tomorrow (July 17).
The Bureau of Meteorology predicts snow down to 800 metres, most likely in the morning.
Katoomba's forecast is for a minimum of 5 degrees and a maximum of 6 with an 80 per cent chance of showers or snow.
It would be the second snowfall of the winter, after a big dumping on June 10 which extended well down the Mountains to Wentworth Falls.
But would-be revellers are reminded of lockdown rules.
While everyone loves to frolic in the white stuff, people are urged to adhere to restrictions.
Blue Mountains mayor, Mark Greenhill, said: "While the presence of snow is wonderful it is absolutely not a reason for people to break lockdown and it definitely must not be a green light for people to come racing up to the Blue Mountains to see it.
"We must all remain in lockdown, stay at home, and not go out for any but the permitted purposes."
And John Hughes, Unit Commander of Blue Mountains SES, said high winds were likely to reduce the chill factor significantly tomorrow. He believed there was only a small chance that the snow will settle on the ground.
"For your own safety, people should remain at home to prevent exposure to both the cold weather and to COVID," he said.