Canberrans keen to avoid a drenching should remember to pack a brolly before setting off for work on Friday.
The capital could be hit by more than half a month's worth of rain in just two days, forecasters have predicted.
Between 15 and 25mm of rain is forecast to fall on Friday, with between 5 and 20mm predicted to follow on Saturday.
The average rainfall for the entire month of May is 47mm, Bureau of Meteorology duty forecaster Miranda Langton said.
Although the forecast might dampen the start to the weekend, there was some good news in the mail, she added.
"There are some showers for Thursday evening," she said.
"Into tomorrow the rain will increase and it will continue into Saturday as well.
"But the skies should be clear by Sunday."
Ms Langton said the downpour would be caused by a low pressure system coupled with a large rain band moving over the territory.