Commuters have been hit by flooding on railways and roads, with warnings of more floods to come as some parts of the UK face up to three inches of rain in the next 24 hours.
Heavy rain overnight in the South West led to the flooding of around 15 properties in Somerset and disruption to rail services between Exeter and Bristol, while flooding is delaying trains between Chester and north Wales.
The Highways Agency also said surface water flooding was causing delays on the A49 near Ludlow, Shropshire. Motorists are being warned to take care on flooded roads in flood plains and in valleys.
The Met Office is forecasting that up to 100mm (more than three inches) of rain could fall over parts of northern England, the Midlands and north and east Wales over the next 24 hours, with some areas receiving more than the average for the whole month of September.
The Met Office is also warning of high winds across south-east England, with gusts of up to 60mph inland and 70mph along the coast, with similar wind speeds in north-east England and eastern Scotland on Monday night and Tuesday.
On Sunday a woman was killed by a falling tree branch in Kew Gardens, London, during rain and gusts of wind close to 30mph.
The Royal Botanic Gardens, Kew, issued a statement which confirmed the tragedy and said: "We are currently working with police and next of kin are being informed."
Kew Gardens said it was closed to the public on Monday "as a precaution" in light of the Met Office warning of severe weather for London, including winds of more than 50mph.
The Environment Agency has urged people to stay safe in the face of flooding, keeping away from swollen rivers and not attempting to drive through floodwater.
Alison Baptiste, flood risk manager at the Environment Agency, said: "We are already seeing travel disruption due to the wet weather and could well see flooding across the country this week."