Drivers are being advised to take extra care following heavy rain throughout Saturday night and into Sunday.
Some roads are passable only to 4x4 vehicles following prolonged rain.
Photographer Gareth Davies captured flooding near the Clicketts, Tenby, and warning signs detailing road closures.
Dyfed-Powys Police said: "Please drive carefully, many roads affected by surface water.
"Councils are aware and dealing as best as they can."
Police said Pembrokeshire had been particularly badly affected but neighbouring Ceredigion and Carmarthenshire also had difficult conditions.
The area around Aberystwyth and the A40 Carmarthen to Llandeilo was also said to have tough conditions to negotiate.
There are flood warnings in place for today for North and West Pembrokeshire and the Western Cleddau.
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