I’d be pleased to see your evidence that 100°+ was ever confirmed by a recognised weather station in the UK before 25th July 2019, when 38.7C (101.6F) was recorded at Cambridge Botanic Gardens.
And a true believer about what?
And so? - what? Nothing at all, except that the last two days have been exceptionally hot, significantly hotter than anything which has been reliably recorded in modern times (ie centuries-scale). And temperatures have been consistently recorded in the UK for longer, and in more locations, than more or less anywhere else, largely because of the many scientifically-minded clergymen in the 19th century who made a daily record taken in the porch of their parish church (Stevenson screens not introduced till the 1880s, of course). 19th century mercury thermometers, many of which survive, were pretty accurate.
Apologies - memory playing tricks. Correction - The first observation to top 100° was in Faversham, Kent in 2003 (38.5C). The Cambridge observation was the highest before yesterday.
You seem to be of the opinion it means something, eg confirms global warming etc...
If I’m wrong, say so.