Water rationing has been introduced in parts of the UK as the Met Office has officially declared a heatwave.
Temperatures were hotter than Ibiza as they topped a scorching 30C in some parts on Tuesday, with areas in the South East taking the decision to ration water supplies due to a lack of rainfall.
This broke a meteorological record known as the June 13th Enigma, the one day of the summer that's never seen the mercury rise above 30C - until now.
The day has traditionally been cooler than any other day in the summer according to data stretching back 150 years.
But yesterday the mercury rose to unprecedented levels at four weather stations, the hottest being Porthmadog in Wales, which hit 30.8C.
Other temperatures recorded were 30.1C in Bridgefoot, Cumbria; 30.1C in Hurn, Dorset; and 30 in Herstmonceux, East Sussex. By comparison, temperatures in Ibiza peaked at a mere 26C.
Met Office spokesman Ollie Claydon told MailOnline: "It's very strange, but June 13 is the only day of summer never to have recorded a temperature above 30c in records that go back to at least 1870.
"But it has now."
Householders in parts of Kent and Sussex were told to restrict water usage to essential purposes only such as drinking and food preparation.
Bosses at South East Water blamed the weather and a lack of rainfall for putting pressure on the local water supply.
The shortages, which hit Wadhurst, Staplehurst, Mayfield and Crowborough, were described as 'woeful' by Tory MP Nusrat Ghani, a Minister of State for Business.
Ms Ghani, 50, who represents the Wealden constituency in East Sussex, said: "I can't believe we are here again in Wealden with unmanned water stations running empty and no updates from South East Water."
It is almost exactly six months since the area suffered water shortages when freezing pipes shut off supplies in the run-up to Christmas, and at least two schools were forced to close yesterday due to having no water.
Speaking last night, South East Water's operations director Douglas Whitfield said: "We've not had any significant rainfall since the end of April and this has put considerable pressure on our ability to treat, pump and supply water to our all customers.
"Together with increased demand, this has impacted the amount of treated water we have in our drinking water storage tanks across the regions.
"We're asking our customers to commit to only using water that's needed for essentials - things like drinking, cooking and hygiene.
"If we can all do that for the next few days, we will be able to refill the network much faster."
As a result of the heat, the UK's solar panels were operating below peak capacity. The National Grid fired-up two coal power stations to help meet demand yesterday.
The hotter it gets above 24C, the less efficient solar panels become due to problems caused by the silicon that many are made from.
Meanwhile, the Met Office officially declared a heatwave in many parts of the country after three consecutive days - June 10, 11 and 12 - when daily maximum temperatures either reached or exceeded the heatwave temperature threshold.
The threshold varies in each county, with the highest of 28C in and around London, and the lowest being 25C in Scotland, Northern Ireland and the north of England.
