Sadiq Khan triggers high pollution warning in London amid sweltering heatwave

The sweltering heatwave gripping the UK has triggered a high pollution warning as forecasters predict the mercury could reach 37C by the end of the week.

London mayor Sadiq Khan said he triggered the capital-wide warning for Thursday amid concerns over “extremely high” temperatures.

He added that it is only the second time this year that the high alert has been used.

An amber heat health watch warning is also in place for much of east and south-east England, with people being urged to try to stay out of the sun between 11am and 3pm.

Mr Khan said: “This week has seen London experience extremely high temperatures.

“The heat, combined with London’s toxic air, a lack of cloud cover and emissions travelling from the continent, means I am triggering a ‘high’ air pollution alert today, for tomorrow, under our comprehensive alert system.

“This is the second time in six months that we have had to use the ‘high’ alert system and shows just why air pollution is a public health crisis.”

Air quality alerts will be displayed at bus stops, river piers, on busy roads and at the entrances to London Underground stations.

In high pollution episodes, adults and children with lung problems and adults with heart problems should reduce strenuous physical exertion, particularly outdoors.

People with asthma may find they need to use their reliever inhaler more often, and older people should also reduce physical exertion.

Anyone experiencing discomfort such as sore eyes, cough or sore throat should consider reducing activity, particularly outdoors.

Temperatures at set to peak at about 35C on Thursday before increasing to a possible 37C on Friday.

This would see the previous July record of 36.7C, recorded at Heathrow Airport on July 1, 2015, toppled.

Paul Gundersen, chief meteorologist at the Met Office, said: “The heatwave conditions will continue across much of England, with temperatures into the mid to high-30s Celsius in many places from the Midlands eastwards on Thursday and Friday and it’s possible that we could break the all-time UK record of 38.5C if conditions all come together.”

The all-time UK high pf 38.5C was set in August 2003.

Despite ever increasing temperatures, yellow weather alerts have been issued over fears of torrential downpours by the weekend.

Mr Gundersen added: “There is the chance of thunderstorms breaking out over some eastern parts of England on Thursday, but it is Friday when we see intense thunderstorms affecting many central and eastern areas.

“Whilst many places will remain dry and hot, the thunderstorms on Friday could lead to torrential downpours in places with as much as 30mm of rainfall in an hour and 60mm in 3 hours.

“Large hail and strong, gusty winds are also likely and combined could lead to difficult driving conditions as a result of spray and sudden flooding.”