Overnight, London and the Home Counties were worst affected by the conditions.
About a month’s worth of rain fell on parts of the Chilterns in four hours – most of it in just two hours.
In south east England, a night of heavy rain forced the closure of an M25 slip road and led to delays on train services.
While there is a risk of some passing torrential downpours in most areas in England and south-east Wales on Monday, parts of central and southern England will be the focus for more persistent heavy rain.
The area covered by the amber warning stretches from Herefordshire and Gloucestershire up towards East Anglia and the Humber, encompassing Birmingham, Nottingham and Sheffield.
Between 100 and 120mm of rain could fall on the worst affected areas on Monday, with further flooding and disruption likely.
