Red weather alert London 2022: Hour-by-hour weather forecast for the duration of the extreme heat warning

The Met Office issued a red weather warning for extreme heat on Friday morning.

London is set to bask in temperatures that could hit up to 40C as the capital prepares for its hottest ever weather.

On the morning of Friday, 15 July, the initial amber alert for extreme weather was bumped to a red alert, which is the highest category of weather warning the Met Office can issue.

The temperature on the night of Monday, July 18 was one of the hottest nights ever recorded in the capital, with many people uncomfortable and struggling to sleep due to the heat.

The extreme heat will affect much of England (Photo: Getty Images)

Here’s the hour-by-hour weather forecast for Tuesday in London

Tuesday, July 19 - Sunny and moderate breeze

  • 12am - 27C - Clear
  • 1am - 26C - Clear
  • 2am - 26C - Clear
  • 3am - 25C - Clear
  • 4am - 25C - Clear
  • 5am - 24C - Partly cloudy
  • 6am - 24C - Partly cloudy
  • 7am - 25C - Partly cloudy
  • 8am - 25C - Partly cloudy
  • 9am - 28C - Sunny
  • 10am - 31C - Sunny
  • 11am - 33C - Sunny
  • 12noon - 36C - Sunny
  • 1pm - 37C - Sunny
  • 2pm - 38C - Sunny
  • 3pm - 38C - Sunny
  • 4pm - 38C - Sunny
  • 5pm - 37C - Sunny
  • 6pm - 36C - Partly Cloudy
  • 7pm - 35C - Partly Cloudy
  • 8pm - 31C - Partly Cloudy
  • 9pm - 28C - Partly Cloudy
  • 10pm - 26C - Clear
  • 11pm - 24C - Clear

What is the highest ever recorded temperature in London?

The highest recorded temperature in London was 38.1C at Heathrow Airport in 2003.

On Monday, the mercury got to within a degree of that - with Kew Gardens hitting a temperature of 37.4C.

Today however is supposed to be hotter, and could see the 2003 record be broken between 2pm and 4pm.

When will the heatwave end?

From Monday, a red heat warning for weather has been issued, which will be active until Tuesday night at 11.59pm, meaning it will be in place for almost 48 hours.

What can we expect from a red warning for extreme heat?

The Met Office said a red weather warning is: “An exceptional hot spell on Monday and Tuesday leading to widespread impacts on people and infrastructure.”

Here’s what you can expect:

  • Population-wide adverse health effects experienced, not limited to those most vulnerable to extreme heat, leading to serious illness or danger to life. Government advice is that 999 services should be used in emergencies only; seek advice from 111 if you need non-emergency health advice.
  • Substantial changes in working practices and daily routines will be required
  • High risk of failure of heat-sensitive systems and equipment, potentially leading to localised loss of power and other essential services, such as water or mobile phone services
  • Significantly more people visiting coastal areas, lakes and rivers, leading to an increased risk of water safety incidents
  • Delays on roads and road closures, along with delays and cancellations to rail and air travel, with significant welfare issues for those who experience even moderate delays