At 0700 AEDT on Monday, the local unit was trading at 87.38 US cents, down from 87.93 cents on Friday.
Early on Monday morning, it fell as low as 87.33 US cents, its weakest level since October 24.
On Friday, the Bank of Japan surprised markets by announcing an increase to its massive bond buying program to kick start its sluggish economy.
The BoJ said it had ramped up its is bond buying program by as much as 20 trillion yen ($A196.92 billion) a year to 80 trillion yen.
On Saturday, China’s official purchasing managers index (PMI), showed that manufacturing activity had expanded at a much slower pace in October.
OM Financial senior client adviser, Stuart Ive, said both events put the Australian dollar under pressure, as traders move to haven currencies like the US dollar.
“The surprise stimulus saw the US dollar strengthen across the board,” he said.
“Adding those global growth fears was the official Chinese PMI coming in weaker than expected but still in positive territory, people will be wondering if the economic slowdown in China will be worse than expected.”
Ive said the weak Chinese data would prompt a greater focus on HSBC’s manufacturing PMI for October due early on Monday afternoon.
“If that comes in with a weak number, we will see the Australian dollar under further pressure,” Ive said.
“I think markets will be holding off until we see that data.”
He added that the HSBC PMI will be a bigger driver for the Australian dollar than the Australian building approvals data for September, which is released an hour earlier.