On Monday, SMHI issued a class 1 warning – the agency's lowest warning level on a three-level scale – for western Sweden, saying an addition 25 to 30 millimetres of rain could fall in the already rain-soaked region.
Heavy rains first moved across the region on Sunday, causing major problems during the evening, including flooded cellars and road closures.
Worst hit were Gothenburg and northern Halland County, where emergency crews were forced to rescue drivers whose vehicles had become stranded in flood waters.
The southbound lanes of the E6 motorway were closed down near Kållered, and a number of smaller roadways in the Gothenburg area were also closed.
Gothenbur-area emergency services received more than 250 calls in a matter of hours in the wake of the downpour.
Most calls concerned flooding in homes, businesses, apartment buildings, and care centres.
“We've even had two cases where we had to go get people out of cars that had gotten stuck in the water,” emergency services spokesperson Per Jarring told the TT news agency.
While the rain let up temporarily after midnight, allowing conditions to improve somewhat, more rain is on the way, according to SMHI.
On many roads, standing water remains.
“That's the biggest problem. I don't think we've ever had so much water,” Mats Olsson, a spokesperson for the Swedish Transit Administration (Trafikverket), told TT.