The declaration of La Niña has the battling building industry bracing for impact.
Wet weather coupled with labour and material shortages have cost builders hundreds of thousands of dollars and forced others to leave the industry amid the past two consecutive La Niñas.
Sunshine Coast builder Joe McGuirk said more significant rain could rock a struggling industry.
"A day of rain can potentially cost you two or three weeks if it falls on the wrong day," Mr McGuirk said.
"We've had instances where we've had rain on days we're doing pool digs and it's cost us up to $10,000 just for that single impact of rain on that single job.
"Commercial builders, where they're going into the ground, could be hundreds of thousands [of dollars in losses]."
In the past 12 months, parts of the Sunshine Coast have received record rainfall, with more than 2.4 metres recorded.
"Some jobs were impacted by 60 days on individual jobs but some jobs you may only lose 10 to 20 rain days," Mr McGuirk said.
Lee Rolley, who runs a building business with her husband Dan, said with a third consecutive La Niña declared, her crews were rushing to finish exterior work before the rain started falling.
"It puts a lot of pressure on site and the guys are working a lot longer hours than what they normally would," Ms Rolley said.
"Dan, he's on site probably more than he needs to be so his work in the office is getting done at three and four o'clock in the morning or five and six o'clock at night."
She said the wet weather pattern cost the business 15 per cent of its annual turnover last year.
"We're having to reschedule all the time. Rather than once or twice, most jobs we're rescheduling four, five, six times," she said.
"It's not just costing you on that job to redo the work. It's costing you from lost productivity on another job."
No sure thing
The La Niña weather pattern declared across eastern Australia increases the risk of heavy rainfall but does not guarantee it.
Master Builders Sunshine Coast regional manager Nicola Scott said builders should prepare for the worst to weather the potential storm.
"We need to just play smart and not hard and make sure that we've got good contingencies in place," Ms Scott said.
"Make sure that we don't over commit and that whatever we are committed to, we're confident we can deliver, communicate effectively, especially with your clients, suppliers, trade contractors.
"That will minimise disputes as well between clients and builders and clients and trades."
Ms Scott said some builders in the region were still catching up on six months' worth of delays.
"Obviously, there's that level of angst that we're now potentially going to experience that same sort of bad weather again, which will impact the industry without a doubt," she said.
"It's not just on our builders and trade contractors in the industry, it's on consumers as well, that are waiting on their homes to be completed, they're in rental properties, they're having to extend their leases.
"We are trying very, very hard and consumers also need to be aware that that we can't predict the weather."
'Perfect storm'
Mr McGuirk said the increased rain over the past two years had compounded labour and material shortages, putting builders in the line of a "perfect storm".
"In the past, when you had rain days, you're able to reschedule a lot quicker because you're able to get those things back on track a lot quicker," he said.
"We're booking four to six weeks, even eight weeks out for certain trades."
He said the past two years had taught him the importance of documentation and communication with clients.
"Everyone's finding it challenging because no-one has experienced this much rainfall," he said.
"Like, they talk about the 1974 floods, but this is just again, and again, and again; it just seems relentless.
"We're hoping it's not as bad as what they're predicting, we hope they're wrong."
