Four flood warnings have been issued for parts of England and Wales on Sunday, while there are 17 flood warnings in place in Scotland.
High rainfall totals have been recorded in the Scottish Highlands, peaking in Cluanie Inn which received 130mm.
Scottish government ministers and officials gathered on Sunday afternoon to discuss the impact of Storm Boelo.
In a statement, the Scottish government said while conditions may ease later on Sunday, there is potential for adverse weather to return in the coming days.
In Aberfeldy, Perth and Kinross, two women were taken to hospital after being struck by a fallen tree at around 12:50 GMT on Sunday, police said.
The towns of the Clyde coast in Scotland have been hit particularly hard by the severe weather. The main Skelmorlie to Largs road has been badly damaged and a number of businesses in Largs were flooded overnight on Saturday.
In Gourock, a boat ended up on the side of the road and there have been reports of power being out in Girvan all throughout Sunday.
In Dumbarton, on the north bank of the River Clyde, Muhammad Zubair Ashraf’s mobile phone shop was flooded overnight.
He estimated between £5,000 and £10,000 of damage was caused and said he was “heartbroken” at the scale of the losses.
Travel has been affected across the country, with police in Scotland warning against unnecessary road journeys.
Ferry services have been impacted, some flights to and from Belfast, Glasgow, Aberdeen and Dublin airports have been cancelled, and train services across the UK have faced disruption.