Credit due also to the MeteoGroup Model Output Statistics, the source of that 26C forecast on Monday - derived from a range of models plus any human adjustment.
One of those situations I would guess when the east of East Anglia could be warmer tomorrow than today as the sea breezes fail to make much progress against the SW breeze.
As you implied a few days ago, a weekend for very careful national introductory comments on all weather forecasts in view of the NW / SE divide.
Julian
Molesey
Surrey