As of 08:00 GMT, there were 56 flood warnings in place in England, 36 in Wales and four in Scotland. There were also 169 flood alerts in place in England, 36 in Wales and six in Scotland.
South-west and north-west England, as well as Wales, are expected to be the worst-affected by flooding.
Storm Bert has caused roads and homes to flood, and led to power cuts. Around 23,000 properties are without power across the UK, according to PowerOutage, a data aggregator.
In Denbighshire, north Wales, five adults and five children were rescued from a house flooded with debris following a landslide on Saturday.
North Wales Fire and Rescue Service said “significant flooding in the area” remained as of Saturday evening. It published footage showing floodwater coursing through a country lane.