Temperatures have reached 40 degrees for the first time on record in the UK, with 40.2 degrees provisionally recorded at Heathrow Airport in London, the Met Office said.
The threshold was hit at 12.50pm as much of the UK sweltered in a heatwave, with parts of England and Wales under a red warning for extreme heat, posing a danger to life, pressure on the NHS and disruption across transport networks.
The extreme heat is fuelled by climate change, which is making every heatwave more intense, frequent and likely, scientists warn.
The new high for daytime temperatures comes after the UK experienced its warmest night on record on Monday, with temperatures remaining in the mid-20s.
The UK Met Office warned temperatures were still climbing early on Tuesday afternoon.
