The country is bracing itself for what could still be the hottest day ever recorded in the UK.
Records are expected to be broken across the UK as the heatwave continues.
Forecasters say temperatures could hit 39°C in southern England, smashing the previous record of 38.5°C recorded in Faversham, Kent, in 2003.
The Met Office said that the mercury had already reached 36.9°C at Heathrow by 1.30pm on Thursday. That's the hottest day of 2019 and a July record. Here's the forecast for all of Wales this week .
But while it's hot here countries all across Europe have been experiencing record-breaking temperatures far in excess of the UK.
Belgium, Germany, and the Netherlands all recorded their highest ever temperatures on Wednesday.
And a red alert has been issued for Thursday in northern France, where a temperature of 40.6°C was recorded.
Here's what has been happening across the continent:
Germany
Germany issued heat alerts for the entire country on Wednesday.
By the end of the day at least 10 weather stations had reported temperatures in excess of 39°C .
Germany's national weather service, DWD, said the town of Geilenkirchen, near the Dutch and Belgian borders, may have experienced a temperature of 40.5°C, coming in at 0.2°C higher than than the record.
Paris
While temperatures in Paris remained below the record-breaking high on Wednesday, Thursday is expected to be a very different story.
Several French cities, including Bordeaux, set new all-time highs above 40°C on Tuesday.
According to the Met Office, the capital will reach its hottest at about 5pm, with highs forecast at 41°C. But Météo-France is forecasting a figure closer to 42°C.
Due to the hot weather several characters and shows have been cancelled at Disneyland Paris on Thursday as well as some attractions.
Belgium
The Belgian town of Kleine Brogel hit a top temperature of 39.9°C on Wednesday, up from the previous record set in June 1947.
Forecasters say temperatures could climb further on Thursday.
A Eurostar train broke down in a tunnel during the worst of the sweltering heat.
Travellers said they were stuck in 40°C heat with no air conditioning after the high-speed Brussels to London train halted near Halle in Belgium for two hours.
They had to get off and wait at the side of the track.
Netherlands
The Dutch city of Eindhoven beat the country's national temperature record with a reading of 39.3°C on Wednesday.
According to the BBC the hottest areas were in the Dutch province of Brabant and across the Belgian border.
One bridge in Rotterdam had to be sprayed to prevent the metal structure from expanding too much in the heat.
Is climate change to blame?
According to the Met Office heatwaves are extreme weather events but research shows that with climate change they are likely to become more frequent.
Forecasters projections show that heatwaves with the intensity of last summer's event could occur on average as regularly as every other year by the middle of the century.
A study showed that heatwaves are now 30 times more likely to occur now than in 1750 because of the higher concentration of carbon dioxide in the atemosphere.
The Earth's average surface temperature is now 1°C higher than the pre-industrial period but that has risen by a greater amount in some regions.
Chief Meteorologist Steve Willington said: "There is a real possibility of records being broken today not only for July but also all-time records.
"The weather setup is broadly similar to the pattern that brought high temperatures to much of continental Europe at the end of June.
"The difference this time is that the wind flow will be more directly from France, paving the way for some exceptional, perhaps record-breaking temperatures."
