According to the BBC...

"England broke its record twice in one day - with a provisional temperature of 36.7C in Merryfield, Somerset, beating the 36.4C recorded in Yeovilton, also in Somerset, hours earlier."

What the BBC are not telling you is that we are talking about RNAS Merryfield and RNAS Yeovilton. RNAS Yeovilton is a frontline Royal Navy air station located in Somerset, serving as one of the Navy's two principal air bases. It is one of the UK's busiest military airfields, working in conjunction with Merryfield.

RNAS Yeovilton started collecting temperature data in January 1964, whereas data collection at Merryfield only kicked-off in May 2021. There's plenty of hot tarmac at both stations, and I've located the exact location of the Stevenson screen at RNAS Yeovilton (pic attached). I have yet to pinpoint the exact location of the screen at RNAS Merryfield - might be worth a trip since it is only 24km distant from the Dee household. Incidentally, the Dee North wall probe managed to max at 33.8°C yesterday.

ADS-B tracking reveals multiple flights operating out of both bases during the afternoon of 25th June, so any one of these could have affected the sensitive temperature probes.