Homes, roads and Tube stations have been flooded while two London hospitals asked patients to stay away after thunderstorms battered the south of England on Sunday.

The Environment Agency has six flood warnings in place across the country’s southeast, while there are 19 alerts for potential flooding active throughout England and Wales.

The wettest part of the country on Sunday was St James’s Park in London, where 41.6mm of rain fell.

Residents in north-east London used buckets, brooms and wooden boards to create makeshift flood defences for their homes, while water gushing from an Underground station was caught on video.

Restaurant manager Mariya Peeva, who lives in Woodford, said her neighbour’s bedroom was flooded, and her son worked with other residents to prevent the rising rainwater from deluging their home.

Ms Peeva, 46, said: “My son went to buy some food from the local shop – by the time he came back the whole street and the pavement were already flooded and the water was coming into our front door.”

Londoner Eddie Elliott, 28, said the flooding was the worst he had ever seen it, after he cycled past Queenstown Road station where the road had been “totally shut down”.

He said: “Having been born and raised in London, I have never seen anything quite like it.

“It stands out as the worst I’ve experienced personally … totally shut down the whole road with buses stood broken down in the water.”

Whipps Cross and Newham Hospitals in east London both urged patients to find alternative treatment centres after they were affected by the downpours.

Whipps Cross Hospital said it was “experiencing operational issues” and asked patients to use an alternative A&E “if possible”.

Newham Hospital had a similar appeal, writing on its Twitter account: “Our Emergency Department has flooded in some areas. We’re still here if you need us but to help us while we fix things please attend a neighbouring hospital if possible. Thank you!”

Standon Calling festival in Hertfordshire was also cancelled due to the floods.

The festival said in a statement: “Unfortunately due to flooding we will no longer be able to proceed with the festival.

“If you can safely leave the site this evening please do so as soon as possible. We are working on getting everyone off site as safely and quickly as possible.”

The Met Office had a yellow warning for storms from Norwich to Plymouth in place until midnight on Sunday.

The rain brought an end to the heatwave earlier this week, but temperatures are set to rise in most places again on Monday as the storms clear, with the mercury predicted to reach 26C in London, 25C in Edinburgh, 24C in Cardiff, and 22C in Belfast.

The Met Office has predicted early cloud in some northern and eastern parts which will move up to Scotland, and sunny spells and scattered showers in most places throughout the day on Monday.