Rail services and roads have been affected as heavy rain fell across most of Wales and parts of England.
Up to 3in (80mm) of rain was expected in south-east and south-west Wales, according to a Met Office weather warning.
Rail services, including the Cambrian and Heart of Wales lines, were among those hit.
Transport for Wales (TfW) advised rail travellers to check journeys before travelling.
Flooding has led to numerous line closures, including between Shrewsbury and Welshpool, Crewe and Hereford. Bus replacements were being organised.
Services were also hit between Chester and both Liverpool and Manchester.
Meanwhile, there was flash flooding across Shropshire affecting some homes.
Traffic Wales said roads in Ceredigion and Powys had been flooded.
TfW and Network Rail said they would monitor the situation and provide extra staff and buses where needed.
North Wales Police said the A525 Marchwiel near Wrexham was closed due to flooding between the junction for the A528 and the Cross Lanes roundabout. A vehicle also overturned on the A494 near Ruthin, Denbighshire.
In Nottinghamshire, three people were rescued by the fire and rescue service from a flooded car at Rufford Ford.
Temporary traffic lights are in place on the A44 at Lovesgrove, Aberystwyth, after the river burst its banks, according to Traffic Wales.
And the A487 road has flooded at Blaenplwyf, near Aberystwyth, and the A483 at Abermule, near Newtown in Powys, which is said to be passable with care.