The Met Office said heavy rain and strong winds were forecast across all parts of the UK, with the heaviest and most persistent showers being in western England and parts of Wales.
River flooding is likely with the possibility of a lot of disruption, particularly across Devon, North Somerset, Warwickshire, Worcestershire and Wales, the Environment Agency said.
Almost 400 properties have been flooded since Tuesday, while 9,000 homeowners have been told they are at risk of flooding, it added.
A 91-year-old woman was found dead in her flood-hit North Wales home after torrential rain caused widespread devastation across the country.
Climate scientists have been predicting more frequent flooding in this country for years, and their models show it is likely to get worse.
Water-logged communities across Britain are braced for more torrential rain and flooding overnight.