The unsettled forecast comes as large numbers of people head to outdoor events across the UK.
Reading and Leeds Festivals and Creamfields in Cheshire are all taking place through the weekend, while Manchester Pride runs from Friday through to Bank Holiday Monday.
In London, Notting Hill Carnival begins on Saturday and continues through Monday, attracting large crowds to west London.
The weather looks likely to be decidedly mixed for festivalgoers and event organisers, with periods of sunshine but also a risk of heavy showers and thunderstorms.
Strong winds could also cause additional difficulties, particularly for those staying under canvas, with exposed areas and locations across the south and south-west of the UK potentially seeing the strongest winds later in the weekend.
The exact timing and location of the heaviest showers and thunderstorms could still change, so those with outdoor plans should keep up to date with the latest forecast as the weekend approaches.
Whatever your plans for the weekend, you can keep up to date with the forecast by checking the Weather website and app.