BEACHGOERS looking to enjoy a heatwave which may see temperatures as high as 40C are being told to avoid nearly 20 English beaches.

Bournemouth Council's Beach Check app is showing red for most of its overcrowded beaches, meaning "avoid" as social distancing is not possible, the Mirror reported.

Sunseekers began arriving as early as 3am at Bournemouth beach to bag the best spots, according to locals. It, and other beaches including Sandbanks and Mudeford Sandspit, are on the "avoid" list.

Meanwhile, the Coastguard has warned people to stay safe after rescue teams had responded to 70 call-outs across the UK before midday today.

Hundreds of people packed on to the beaches across Britain as early as 9am, on what could be the hottest day of the year so far.

Temperatures are forecast to rise to 37C (98.6F) in London and the South East, with the second day of a heatwave expected to last until at least Sunday.

READ MORE: Climate crisis: 30C summers set to become ‘norm’ in Scotland

HM Coastguard said around 70 call-outs had been made by midday on Friday, which is "above average for this time of year".

The Coastguard reported its busiest day for more than four years as it dealt with 329 incidents on July 31, when the UK recorded the hottest day of the year and the third warmest on record, with the mercury rising to 37.8C (100.04F) at Heathrow Airport.

Matt Leat, head of infrastructure and technology lead at HM Coastguard, said this weekend could see a similar number of call-outs as families take advantage of the heatwave.

Speaking to the PA news agency, Leat said: "The coast is very busy today and that's grown across the morning and will continue to grow as the day goes on.

"Looking back to last Friday (July 31), we are going to hit that many number of call-outs potentially today and this weekend."

Leat urged the public not to use inflatables at the beach as they get blown out to sea, and to check the tide to keep safe and to look out for each other.

He said the number of people on UK beaches this weekend "will be up there" with bank holidays, adding: "It's highly possible some of the beaches are the busiest in a number of years."

READ MORE: Police called to 'large disturbance' at Portobello Beach

Leat added: "Our responders are very much prepared and geared up for the weekend ahead.

"We will be on patrol and ready for anyone who needs help.

"But we are asking the public to take an element of self-responsibility and think about what they do when they go out to the coast."

Meanwhile, the RNLI has called on beachgoers to follow water safety advice and adhere to social distancing.

Last week, the charity carried out 30 rescues in one day on just one beach in Cornwall.

Anyone who sees a person in trouble should alert lifeguards or call 999 and ask for the Coastguard.