Can it squeeze out another 1.5C?

No

Northolt 35C

Cloud building quickly now.

metars are instantaneous readings and the temperature can fluctuate a lot in the 30min intervals (either due to clouds like today or due to changes in wind direction).

Cloud really piling in now - heavy overcast. Still steamy but at least keeping the temp down a little. Temp: 30.2C

Can see on the satellite https://en.sat24.com/en/gb cumulus building up on all the hills surrounding the London basin, including the North downs.

Only a few small cumulus clouds here.

Temperature has now reached 34.0C. Just 0.5C to go to equal the figure from 31 July.

35C on the Heathrow METAR.

A few clouds around here nudging the temperature down a point or two

https://www.blackbusheairport.co.uk/weather/

35C....Think that might be it now for Heathrow / Northolt. Up until 3pm it was constant sunshine which got the temps to 35C but a lot of cloud about now and building quickly so that the sun is in and out. I expect that will be the highest temp now until at least 2021. A great spell of heat though, loved it!

Hopefully a couple of days of storms now would be lovely

Do not discount tomorrow!

too much instability in the atmosphere tomorrow. Will be cooler than today if anything. The fat lady may not have started singing yet, but she's definitely started lubricating her tonsils in readiness.

I get what you are saying, but that’s not a guarantee in itself that cloud will develop everywhere. It does increase the chance though.

I have a feeling we've reached the maxes for today as well.

I think, hope and pray that that is it for any chance of a new record until 2021. While tomorrow will be similarly unpleasant, there appears to be a greater chance of cloud and storms developing and so I expect maxima to be lower than today.

Thank heavens for that!

ha well spotted 😉  My screen is rather dark in the sun so i missed that one.

Hotting up across N England today, the easterly cooling effect has gone.

31c at Doncaster and York.

Just hit 28.0c here with hazy sunshine.

30.9C at Leeds uni. Certainly not a record by any stretch but a hot day regardless.

Dew point is also 21C.