Weatherzone meteorologist Max Gonzalez said that while Canberra had been enjoying clear skies and temperatures higher than the June average, residents shouldn't get used to it.

"The bulk of the rain will fall on Saturday, when we’ll see between 25mm and 50mm of rain as a low pressure system forms over the Tasman Sea bringing strong winds and rain to the south of New South Wales,” he said.

"On Friday, Canberra will receive between 2mm and 8mm of rainfall, which will be widespread although areas west of the Brindabellas could see up to 15mm."

Mr Gonzalez also warned temperature over the weekend would drop lower than the June average. Saturday was expected to reach a maximum temperature of 13 degrees.

"Sunday however will feel far colder due to strong winds and rain despite the forecast being 13 degrees,” he said. “It’s more likely to feel closer to 10 degrees in Canberra on Sunday."

Mr Gonzalez urged Canberrans to make the most of fine temperatures on Wednesday before cloud increased late on Thursday afternoon as the cool the change arrived.

"Wednesday should see mostly fine conditions after a little fog in the morning which brought visibility down to around 300 metres near the airport, but this will burn off by late morning as we move to a top of 15 degrees,” he said.

Mr Gonzalez said temperatures in Canberra dropped to about -1 early on Wednesday morning and would linger a degree or two either side of freezing on Thursday and Friday mornings.

"Normally we would see a greater amount of frosts on these mornings but there hasn’t been much moisture in the Canberra region of late," he said.

"Monday should be the coldest morning next week and we can expect frosts given the remaining moisture from rainfall over the weekend."

Mr Gonzalez said temperatures during the morning next week could be the coldest of the year and frosts were likely to be common.