Canberra is set to shiver through its coldest day this early in the year since 1970, with a top temperature of just nine degrees forecast for Friday.
Bureau of Meteorology forecaster Anita Titmarsh said the mercury was also likely to drop to freezing point in the early hours of Friday morning, with an 80 per cent chance of rain in the capital.
The potentially record-setting day will be an abrupt change, coming less than two weeks on from the end of the hottest April in the ACT since record-keeping began 75 years ago.
Ms Titmarsh said it was likely to feel more chilly than it was in reality, with winds of 25-35 kilometres per hour tipped to hit Canberra on Friday.
"Those are some quite strong winds, and there is some rain developing, so that nine degrees will probably feel even colder," she said.
"There's a cold front coming up from the south, and they tend to bring quite sharp changes."
There is a chance of a thunderstorm and hail before the rain starts to clear in the capital on Saturday, though showers are still likely that morning and in the early afternoon.
It won't be quite as cold on the weekend, with a top of 14 degrees predicted on Saturday and 16 on Sunday, by which time the rain should largely have cleared.
The ski fields are set for a bumper few days, with the first major snowfall of the season at Thredbo on Thursday as the temperature hovered around -1 degree.
Thredbo communications manager Susie Diver said snow was settling to about mid-mountain, with more than 50cm of fresh snow possible at the resort between Thursday and Sunday.