into a river following heavy rain.
The children and two adults escaped through the roof of the car with the help of fire crews at about 18:20 BST.
All four were checked by paramedics at the scene, near Cae’r Odyn Woods, Cilcain, Mold, North Wales Fire and Rescue Service said.
More than 60mm (2.3in) of rain fell in parts of north Wales overnight – June typically sees about 85mm (3.3in).
Earlier, another driver was rescued from his van and people had to be evacuated from their homes.
Firefighters from Wrexham responded after reports a van driver was stuck in his vehicle on Cefn Road at 06:00, while crews evacuated seven properties in the Bagillt Road area of Greenfield, Flintshire, at 06:50.
A Met Office weather warning for rain in north Wales and Powys is in place until Thursday.
The basement of Welshpool Town Hall and adjacent shops and houses were flooded.
The River Alyn burst its banks at Rossett, Wrexham, where it was recorded at its highest level – 2.11m (6ft 10in) – since a new gauge was installed in 2010.
The Alyn pub, next to the river, was under water. Duty manager Becca Pierce said fences had been put up, but the flooding was only affecting the garden.
“It is probably going to get worse. It is very different from what it is normally like. I’ve worked here for about three years and I have never seen it like this,” she said.