Vast swathes of the United Kingdom are under thunderstorm warnings as forecasters predict up to 40mm of rainfall within hours. Yellow alerts came into force across Northern Ireland, Wales, southern Scotland, and most of England at 11 a.m., accompanied by warnings of winds up to 45 mph in some areas.

The adverse weather conditions have raised concerns about driving conditions, public transport delays, and potential flooding.

Despite the warnings, festival revellers across the country have largely refused to let the rain dampen their spirits. At London's Notting Hill Carnival, celebrating its 60th anniversary, attendees shielded themselves with cardboard and umbrellas during the family day events. The main parade on Monday is expected to draw larger crowds.

Those marching in Sunday's parade were undeterred, with one woman proudly holding the DR Congo flag

The flags of Barbados and Jamaica were also on show as some marched in ponchos down the streets of Notting Hill

Thousands attending the Reading and Leeds Festivals donned ponchos and braved muddy conditions throughout the weekend. Some festival-goers were seen playing in the mud, while others sought shelter under plastic coverings.

Friends arrived armed with their rain ponchos for Saturday at Leeds Festival

Festivalgoers sheltered from the rain in plastic ponchos yesterday as they walked through the muddy site at Reading Festival at Little John's Farm, Reading, Berkshire.

The girls did not seem to have a care in the world as they had fun in the mud

The Met Office warned of intense downpours, frequent lightning, thunder, and hail. Showers are expected to be concentrated across western areas in the afternoon, with some longer spells of rain anticipated in southern Scotland and northern England. The south and east of the country are expected to remain drier with some sunny spells, though isolated showers are possible.

Thunderstorm warnings are in place across most of the country and extend into this evening

Temperatures are forecast to be mild, with highs of around 23C (73.4F) in Norwich, 22C (71.6F) in London, 21C (69.8F) in Cardiff, and 18C (64.4F) in Glasgow. Monday, a bank holiday in England, Wales, and Northern Ireland, is expected to have a fine and largely dry afternoon with some scattered showers.

Elsewhere, the England Men's cricket team's Test match against Pakistan in London was halted due to rain. Environment Agency flood alerts are in place for seven areas, indicating that flooding is possible. This weather follows a period of hot weather across the UK, which contributed to extremely dry conditions and is on track for one of the hottest summers on record.