It could be rather close to a date record - depending on which reading you go off, the record for the 23rd of September is 28.4ºC in Loughborough in 1895. The climate return for Stratfield Turgis lists the readings as 'manifestly unreliable', so I have discarded the 30.6ºC.
Fresher air is arriving, with temperatures settling closer to average
London and parts of the southeast hold onto the warmth a little longer, with highs reaching 27-28°C on Friday before turning fresher on Saturday
Expect chilly starts, followed by warm afternoons ❄️👉🌡️