“Strong and gusty east to northeasterly winds” may lead to some disruption on Christmas Day, the Met Office has warned.
It has issued a yellow weather warning across a large swathe of Wales for Thursday.
Gusts of up to 55mph (89km/hr) are expected widely, it said, with up to 65mph (105km/hr) gusts along exposed coasts and high ground.
It has also warned of possible disruption to travel and power supplies.
“Large waves will be an additional hazard on some coasts,” the forecaster added.