LONDON — Britain’s national weather service on Friday issued the most severe warning it has for heat, putting parts of England under a red alert for Monday and Tuesday. It’s the first time the warning has been applied to extreme heat, said Alex Deakin, a meteorologist with the service, known as the Met Office.
That means the heat will be so severe that it can adversely affect people of all ages, not just the most vulnerable, possibly leading to “serious illness or danger to life” the Met Office said. An amber warning, the second-highest level, was extended in parts of Scotland.
Meteorologists in Britain have been warily eyeing the days ahead, bracing for temperatures never experienced before in a place where umbrellas are used more as shelter from drizzling rain than as shade from the beating sun.
Mr. Deakin said Friday it was “very highly likely” that Monday or Tuesday could break the record for the highest temperature officially recorded in Britain, which was 38.7 degrees Celsius (101.6 Fahrenheit) on July 25, 2019.
“Exceptionally” high temperatures above 35 Celsius (95 Fahrenheit) are expected between Sunday and Tuesday before settling into cooler — or not as hot — weather for the rest of the week, the forecast says.
In London this week, shops prominently displayed hand-held battery-operated fans, and the mayor activated emergency protocols to help homeless people find places to stay cool. The Met Office warned there could be disruptions of services, including water, electricity and travel, and related illnesses such as heat exhaustion. The National Health Service issued an advisory with tips on how to cope.
The Drapers Arms, a pub in North London, said it would not open on Monday and possibly other days because the forecast was unacceptable. Like other historic buildings, and many homes in Britain, the pub does not have air conditioning.
“It gets too hot in the kitchen,” said Melanie Hunt, an assistant manager. “They can’t work under those conditions. It is for the staff, especially the kitchen, but the front of house as well.”
“We have fans but I don’t think they do too much, unless you are right in front of it.”
July has already been warm in parts of Britain. Summer days in southern England typically fall in the mid-30s, although the mid- to high 30s are becoming increasingly common, depending on the region.
Sunday was the hottest day so far this year in Scotland, which hit 29.3 Celsius (84.7 Fahrenheit), and in Northern Ireland, which reached 24.3 Celsius (75.7 Fahrenheit), Mr. Deakin said in an interview on Thursday.
“We get huge swings,” he said.
Last summer, as temperatures hovered around 30 Celsius, the Met Office issued its first ever extreme heat warning, and it warned that more would come. “Although hot weather can often be seen as ‘good news’ and is enjoyed by many, it can have serious consequences,” the Met Office said at the time. “Research shows that, as a result of climate change, we are now much more likely to see prolonged spells of hot weather here in the U.K.”
“This isn’t just a typical July hot spell,” said Mr. Deakin during an online presentation this week, fielding questions from Twitter users about vacation plans, when they could expect rain (possibly the last weeks of July), and whether businesses or schools would need to close (it’s up to them, Mr. Deakin said).
Despite the bracing expectations, Britain may not be as bad off as some countries.
This week, temperature forecasts exceeded 104 degrees Fahrenheit in dozens of cities in eastern and southern China. Italy is in the grip of a drought, exacerbated by high temperatures, that has led to water rationing. The scorching heat reflects a global trend of increasingly frequent episodes of extreme weather driven by climate change.
“The highest temperatures experienced in the U.K. tend to occur when our weather is influenced by air masses from continental Europe or North Africa — as it will be at the weekend,” Dr. Mark McCarthy, the head of the Met Office National Climate Information Centre, said in a statement.
On Mr. Deakin’s Twitter chat, one man said he was concerned about the heat combined with high humidity in Britain, a combination that he said “will cook us.”
“It’s a different kind of heat,” Mr. Deakin agreed, referring to how it feels in hotter climates such as in Dubai, where temperatures are surpassing 38 Celsius (100 Fahrenheit) regularly this week. “That dry heat you get in the desert is easier.”
“The more moisture there is in the atmosphere, so the more humid it is, the harder it is for the body to sweat,” he explained, while warning listeners to wear a hat, apply sunscreen and drink plenty of water.