The fourth heat wave of the season is underway around here, but this is hardly a shadow of what Europe has experienced this summer. The continent has been running fevers.
The U.K. Met Office confirmed on Monday that the 101.7 Fahrenheit recorded Thursday at the Cambridge Botanic Garden was the highest temperature in the United Kingdom in records dating to 1914.
That beat the 101.3 at Faversham, Kent, in August 2003, the year of a devastating heat wave blamed for more than 50,000 deaths across Europe, although the real number can never be known.
Last week, Belgium, Germany, Luxembourg, and the Netherlands all recorded their highest temperatures on record, as did Paris (with a reading of 108.7). France had set a national record in a June heat wave.
What’s going on over there?
As the Met Office pointed out, while the global temperature has increased a bit more than 1.5 degrees Fahrenheit since the Industrial Revolution, some places have warmed more than others.
That includes the Arctic and northwestern Africa, where temperatures have increased by about 3.5 degrees.
That was a factor in last week’s heat in Europe.
As is often the case around here, the heat occurred to the west of a center of high pressure, or heavier air that tends to repel cloudiness and allows the sun to bake the ground.
Winds circulate clockwise around high centers, so areas to the west of the center experience warming winds from the south and southwest.
That particular high was centered over Central and Western Europe, said Tyler Roys, an AccuWeather.com meteorologist who specializes in European weather. The southerly winds on the west side imported hot air that had been “bottled up” in Morocco, Algeria, and Tunisia in the first half of July, he said.
Since the air primarily was coming off land, it wasn’t nearly as moisture-laden as the air masses we typically get during heat waves around here.
That allowed the temperature to soar into triple figures; dry air heats better. When the atmosphere is laden with water vapor, some of the sun’s energy has to be spent on evaporating the moisture, rather than heating the ground.