The Met Office has issued a weather warning for large parts of Mid Wales throughout Saturday, with winds of up to 40mph forecast for inland areas.
The yellow warning for wind is in place on Saturday, August 5 between 6am and 9pm.
The Met Office has said that inland gusts between 35 and 40mph are possible, with coastal areas set to be battered by gusts of up to 65mph.
Alongside the "unseasonably windy conditions" will be showers and "longer spells of rain", the weather service said.
The warning covers many towns and villages in Brecon and Radnorshire, including Crickhowell, Brecon, Builth Wells, Rhayader, Llandrindod Wells, Ystradgynlais and Llanwrtyd Wells.
The Met Office has said there is a good chance of longer journey times or cancellations as road, rail, air and ferry services are affected, and there is a chance that some roads and bridges could close too.