Monthly temperature records smashed in Europe beneath sprawling heat dome
By MATTHEW CAPPUCCI | The Washington Post | Published: April 2, 2021
Temperatures in much of Europe are running 20 degrees or more above average as an early-season heat dome, a strong high-pressure system several miles up in the atmosphere that traps heat below, remains parked over the area. Monthly records have fallen in at least three countries as the region gets a taste of what could be another anomalously hot summer in store.
It's the latest in a series of heat records that are disproportionately outpacing the occurrence of cold extremes, largely the product of a changing climate and a planet whose temperatures are skewed hot.
It comes at the same time as mild temperatures in Japan brought the earliest peak bloom to Kyoto's cherry blossom trees in at least 1,200 years of bookkeeping. Record warm temperatures have extended to much of Asia, with another area of exceptional warmth concentrated in southern China.
On Wednesday, Germany and the Netherlands set all-time March records, reporting highs of 81 degrees and 79 degrees, respectively. Kew Gardens, about 10 miles west of London on the River Thames, hit 76.1 degrees on Tuesday, the warmest March temperature set in the United Kingdom since 1968.
Climate historian Maximiliano Herrera has been tracking the records and their historical context, and describes the episode as "historic."
France also saw record warmth on Tuesday as the nation's average temperature was higher than any other March day in recorded history. More than 220 weather stations, or roughly 37 percent of France's network, observed new maximum March temperatures.
Jersey, the largest of the Channel Islands just 10 miles offshore of northern France, hit 73.2 degrees on Tuesday afternoon, the highest temperature ever recorded in March in more than 125 years of records.
Guernsey, another island 15 miles to the northwest, hit 67.6 degrees, its warmest March temperature on record dating back to 1843. The Guernsey Met Office is calling for similar temperatures near 68 degrees on Thursday, but records are not in jeopardy, since the calendar has since flipped to April.
Alderney, Guernsey's smaller sister island and the most northerly Channel Island, only made it to 54.1 degrees on Tuesday thanks to a strong northeasterly wind.
In Switzerland, a number of monthly records fell at individual weather stations on Tuesday, including some at high elevations of the Alps. That demonstrates just how deep, or how high off the ground, the warm air mass was, something to be expected with a large-scale heat dome. Grimsel, a mountain pass in south-central Switzerland, made it to 51.6 degrees, surpassing the previous record of 50.7 degrees set on March 11, 1997. Chaserral, a roughly mile-high mountain peak in northwest Switzerland, climbed to 57.2 degrees, compared to the previous record of 55.4 degrees in March of 1990.
Other stations in Switzerland beat their previous records by two degrees or more, whereas typically records are only broken by a few tenths of a degree.
Belgium and Austria saw 13 and 29 stations, respectively, break local monthly records on Tuesday, with records falling in Spain and Oman as well. Belgium missed its national monthly record temperature Wednesday by just half a degree, but set a new March record for the national average temperature.
Wednesday also witnessed a new monthly record in Paris of 78.8 degrees, beating out the March 25, 1955 record by more than half a degree.
Meanwhile France's average maximum temperature on Wednesday was the warmest on record for March, hitting 85.6 degrees in the southwest part of the country. And Luxembourg hit its first 77-degree reading ever observed in March.
Farther east, India has been flirting with records, with temperatures rising above 114 degrees in spots as summer heat already builds. Hong Kong also recorded a number of records as well.
The heat in Europe is thanks to a dome of high pressure that's brought clear skies, sinking air and unusual warmth. The heat has been enough to expand columns of air vertically such that the "halfway" mark of the atmosphere is now about 656 feet higher than typical.
In the coming days, the heat dome over Europe will relinquish its grasp and dissipate some, while a new, even more formidable area of high pressure is forecast to become established over Iceland and the northern United Kingdom.
The late-March temperature records are the latest in a string of anomalous warmth to plague Europe in recent years, fitting into a pattern of more frequent and intense temperature extremes influenced by climate change. Much of western Europe spent late February beneath an equally impressive heat dome with temperatures 25 degrees above normal.