Britain will experience its hottest temperatures of the year on Sunday – before thunderstorms and heavy rain bring an end to the sunny conditions that the country has enjoyed over the past few days.

The Met Office forecasts temperatures will peak at around 27C before the wet weather arrives. Western areas, including parts of Scotland, Wales and Northern Ireland, will be the first to encounter the storms.

The UK recorded its highest temperature of the year on Thursday, with a peak of 24.6C recorded in St James’s Park in London, forecasters said. Some were expecting to see another record-breaking day on Friday, but temperatures across the country fell just short.

However, record temperatures are likely to be broken again on Sunday as areas of the UK experience warm, humid conditions. Simon Partridge, a meteorologist at the Met Office, said central and south-eastern parts of England were likely to be the hottest.

The change in weather will occur because the high-pressure conditions that have blocked incoming rain clouds for the past few days are likely to retreat to Scandinavia. As a result, pressure will fall across the UK.

The Met Office said three yellow thunderstorm warnings were now in place for parts of the UK on Sunday.

One covers most areas of the west of the UK, including the majority of Wales, where thunderstorms are expected between midday and 10pm. The second warning is for the ­western half of Northern Ireland between 11am and 7pm. The third warning is for western parts of Scotland and runs between 2pm on Sunday and 4am on Monday.

People in areas with a yellow warning should expect some disruption, especially to travel. Spray and sudden flooding could lead to difficult driving conditions and there is a slight chance of power cuts, the Met Office added.