Wimbledon final Sunday is hottest day of the year

Thermometers expected to read 30°C or higher by the end of the day in the south

As Wimbledon final fever swept the nation, temperatures soared to their hottest levels of the year in a fine weekend across the country.

Police used Twitter to urge tennis fans to keep drinking water and seek out shade, as air temperatures in the sun on Centre Court hit a balmy 40°C.

Today at Heathrow airport observation stations reported a maximum of 29.7°C, the year's highest and beating yesterday's record of 28.1°C. A Met Office spokesperson said there was a good chance of the mercury climbing above 30C before the end of the day, which is the average threshold for their "Heat-health watch" system.

The average maximum temperature for July in England is 20.9°C.

And while Barclaycard chief executive Val Soranno Keating said good weather last month contributed to the highest rate of consumer spending in 18 months, people were being warned about the risks brought by the exceptional sunshine.

It emerged yesterday that the hot conditions had claimed their first casualty, as a boy died while swimming in a lake in a disused quarry near Malvern.

West Mercia police are not treating the incident as suspicious, and issued a warning to anyone considering a swim to cool off, saying: "We would appeal for people to recognise the risks associated with water and act responsibly."

Yesterday the London Ambulance and West Midlands Ambulance Service both recorded their busiest days of the year so far, with numbers of callouts beating the traditional peak around New Years' Eve.

Staff in the London control room answered 6,102 calls, compared to 4,592 just two weeks ago.

Director of service delivery Paul Woodrow told the BBC this was in part down to alcohol consumption, and said: "We always see a rise in 999 calls in hot weather. I would urge all Londoners out enjoying the hot weather this weekend to stay safe."

Back at Wimbledon today, Andy Murray's push for an historic victory was met with "dehydration, sunburn and heat exhaustion" for some according to Katherine Eaton, regional events manager for St John Ambulance London. She said: "We've had a busy weekend at Wimbledon. Our volunteers are determined to be the difference by making sure that everyone has access to essential first aid."

Met Office weather forecaster Alexander Burkill said it looked set to be a prolonged period of dry weather, the likes of which we haven't seen since the two-week heat wave of July 2006.

Though temperatures will dip slightly around Wednesday, he said the outlook was largely fine and next weekend will see a return to 28 or even 29°C.

After around 10 days the weather will take a cooler turn. British sun worshippers should make the most of it while it lasts, while staying safe and hydrated.