The Met Office has issued a yellow warning for rain across mid and south Wales on Sunday.
The warning came into effect on Saturday night and will last until 11am on Sunday afternoon.
20-30mm of rain is expected to fall with 50-60mm in some mountainous areas in the south.
The ground is already saturated throughout Wales as the country has seen continuous extreme wet weather from both storms Ciara and Dennis.
Capel Curig in north Wales recorded a record for rain with 80mm in 24 hours.
The warning covers fifteen local authorities in Wales:
- Blaenau Gwent
- Merthyr Tydfil
- Neath Port Talbot
- Rhondda Cynon Taf
- Vale of Glamorgan
While there will not be as much rainfall is last weekend, Natural Resources Wales is urging people to take extra precautions.
Following heavy rain overnight, National Resources Wales have issued 12 flood warnings covering River Severn, River Teme, Upper Dee Valley, River Vyrnwy and Lower Dee Valley.
There are also 28 flood alerts in place.