This years are from weatherobs.com.
2019s are from reading through the historic thread on TWO, I posted them on the hour when I could.
35.5C was the highest at 1pm back then but I didn't say where.
It's also worth noting that there can be huge spikes between the hourly readings, eg the Met tweeting that 35.9C had been reached at Heathrow in 2019 even when the last hourly reading was 34.3C.
I think if we can see a 36C (even rounded) by 1pm then the record is on today. Cambridge airport was 35C rounded on the 12:20 METAR.
Originally Posted by: Rob K