TAMPA, Fla. (WFLA) — London reached 104.4 degrees F on Tuesday, not only breaking the city’s all-time record high by an astounding 4 degrees Fahrenheit, but also breaking the United Kingdom’s all-time record by almost 3 degrees. Then shortly after, the city of Lincolnshire reached 104.5 surpassing London.
The extreme heat had been over Portugal and Spain the past few days, where temperatures reached 115 degrees, wildfires raged, and more than 1,000 people died from the heat. On Tuesday, the heatwave centered over the UK.
In total, the UK Met Office says 34 cities had high temperatures which surpassed the former highest UK temperature of 101.7 degrees. It is difficult to break all-time national records, but to do it by a few degrees, and in dozens of locations is alarming.
Heat of this magnitude is difficult to achieve in London because of how far north the city is. It may be surprising, but the city of London is further north than any continental US city, and even the city of Calgary in Canada. And since it is near the cool North Atlantic Ocean, weather conditions have to line up near perfectly to produce historic heat.
The temperatures experienced in the UK are simply unprecedented—meaning they have never occurred in the UK record.
The graph below shows all the daily maximum temperatures in London since 1948 in black. The red line represents 2022. The top red dot is Tuesday July 19, 2022. It is clearly off the charts.
Climate scientist Dr. Simon Lee pointed out (below) that 40 Celsius (104 °F) is so far right of the London temperature distribution that, in statistics, qualifies a 5 sigma event. Meaning it is 5 standard deviations away from the mean. Taken at face value, using the London historical record as a guide, this event should be virtually impossible.
But that would only be true for the historical climate and that climate is now history. Since the late 1800s the Earth has warmed due to the burning of fossil fuels and release of heat-trapping greenhouse gases. And because of that we now exist in a new, warmer climate, with a shifted temperature distribution, making it easier for seemingly impossible extreme heat to be reached.
So while heatwaves are not caused by climate change, there’s no doubt climate change pushed it over the top. And scientists are clear that this unprecedented heat will soon become routine, perhaps occurring ever few years by mid to late century, if greenhouse emissions continue business as usual.
A high amplitude heat dome is responsible for causing the heatwave, produced by large undulations in a very amplified jet stream. That is how most heat domes form. And typically large waves in the jet stream continue up and down stream along the jet stream, so multiple heatwaves around the globe are common.
As a consequence, concurrent heat waves were also present in the Middle East and in the South Central US.
In southwest Oklahoma one town hit 115 degrees Tuesday—a very rare event but not unprecedented for this area. Still, the chances of this happening are slim.
The bottom line is that climate change, and science’s knowledge of it, has advanced so far that scientists can now say with confidence that every heatwave on Earth is now made more likely and more intense by climate change.