High-altitude weather map shows massive heat dome centered over France on Thursday. (PivotalWeather.com)

(This report has been updated.)

For a third straight day, a ferocious heat wave is baking large parts of Europe, and the exceptionally high temperatures are making history. On Friday, the town of Gallargues-le-Montueux in southern France hit 114.6 degrees (45.9 Celsius), the hottest temperature ever recorded in the country.

The scorching temperature easily surpassed, by more than 3 degrees, the previous record of 111.4 degrees (44.1 Celsius) set in the southern town of Conqueyrac in France’s historic 2003 heat wave, which was blamed for 15,000 deaths.

Etienne Kapikia, a forecaster for Météo-France, the country’s meteorological agency, tweeted that 13 different locations had surpassed the 2003 record.

The heat was so intense that, for the first time since initiating its heat warning system (after the 2003 heat wave), Météo-France declared a red alert, the highest level, for the southeast part of the country Friday. It remains in effect until 4 p.m. local time Saturday.


Temperature difference from normal over France and central Europe simulated by the European model Friday afternoon. (WeatherBell.com)

France’s prime minister Édouard Philippe described the heat as exceptional in its precocity and intensity and called for the the utmost vigilance.

Historic heat has scorched western and central Europe since Wednesday, when national June temperature records fell in Germany, Luxembourg, Andorra, Poland and the Czech Republic.

Hundreds of heat records for the month of June (in some places, for any month) have fallen in individual towns and cities since the heat wave began, many surpassing 100 degrees (37.8 degrees Celsius).

In Spain, where temperatures rose above 104 degrees (40 C) Thursday, intense wildfires erupted in its Catalonia region, charring 16,000 acres, according to the BBC. CNN reported one blaze began when “manure self-ignited."

It’s not just daytime temperatures that have been exceptionally warm. Temperatures at night have also been record-setting, presenting a dangerous situation for those without access to air-conditioning.

Météo-France tweeted that several locations had observed their warmest low temperatures ever recorded in any month Thursday morning, remaining above 75 degrees (24 Celsius).

Several other countries could challenge long-standing heat records into the weekend.

From Spain to Poland, temperatures are forecast to be 20 to 30 degrees (11 to 17 Celsius) above normal through Saturday. Actual temperatures should surge to at least 95 to 105 degrees (35 to 40 Celsius) over a sprawling area.

The highest temperatures compared to normal shift from western Europe Friday to central Europe on Saturday.


Temperature difference from normal predicted by European model Saturday. (WeatherBell.com)

Madrid topped 100 degrees (37.8 degrees Celsius) Friday afternoon and high temperatures were predicted to top the century mark through the weekend, perhaps approaching 105 (40.6 Celsius) Saturday, its highest temperature on record.

In Italy, Florence, Rome and Turin were under the country’s highest heat alert level, the Associated Press reported.

The heat wave commenced Wednesday, when numerous June heat milestones were set:

  • France’s meteorological agency, Météo-France, tweeted that the country’s average high of 94.8 degrees (34.9 Celsius) was its highest recorded in June. The low temperature in Nice, on the French Riviera, was 78.8 degrees (26 Celsius) Wednesday, the warmest ever recorded in June.
  • In Germany, a weather station in Berlin soared to 101.5 degrees (38.6 Celsius) Wednesday afternoon, becoming the highest temperature recorded in the country during June.
  • Poland set its June temperature record, with a high of 100.8 degrees (38.2 Celsius) in Radzyń in the eastern part of the country.
  • The Czech Republic set a June record with a temperature of 102 degrees (38.9 Celsius) in Doksany to the northwest of Prague.

On Thursday, France’s Carpentras soared to 106.3 degrees (41.3 Celsius) Thursday, the first time any location in France had exceeded 41 Celsius during the month of June, until the same town hit an even higher temperature on Friday. The city of La Rochelle in southwestern France hit 104.9 (40.5 Celsius) Thursday, topping 40 Celsius for the first time in its history.

A main cause for the massive early-season heat wave is a pair of powerful high-pressure systems. One is near Greenland, and the other is over north-central Europe. As they become linked and flex over coming days, forming a massive heat dome, they’ll also act to block a low-pressure system to their south, which would draw cooler air over Europe.

“Europe is currently under historically strong upper ridge,” Mika Rantanen, a meteorologist in Finland, tweeted Wednesday. An upper ridge is the technical term for this extensive zone of high pressure or heat dome.

The upper-level ridge is a double-edged sword. It suppresses cloud cover, allowing the sun to bake the land surface, and its circulation can draw even more heat into affected areas.

In this instance, the main heat feed is known as the “Spanish plume,” sometimes also referred to as the “Sahara plume.” The hot air plume, sourced from deserts in Spain and the Sahara, is surging through much of Europe. The result is excessive heat, and severe thunderstorms at times in some places.

The broader weather pattern behind this heat wave has connections to the stagnant high-pressure zone responsible for the big Greenland melt event in mid-June that has been breaking records for longevity. Such patterns may be becoming more common in a warming world.

Although this heat wave is set to peak Friday (in western Europe) and Saturday (in central Europe), it will probably stay hot through the weekend especially in the south. Any notably cooler air holds off until next week, and it may primarily target northern Europe as the general hot pattern holds in place to the south.