It will be 30C season soon but unlikely this month. The only occasion this happened in May in the last 60 years was 2005 on the 27th when 32.1C was reached.
A low pressure system to our west was responsible for sucking up hot air from Iberia.
The incidence of 30C has increased this century. The level of 86 Fahrenheit used to be very rare in the Seventies and Eighties but as this graph below shows it has been getting more common.
The highest incidence of 30C days happened in 2018, the summer that seemed to go on and on; an extended dry spell helped contribute to a large blaze on Wanstead Flats during the day of the World Cup Final.
What about the likelihood of 30C days this summer? The coming pattern, according to the GFS, looks like June could see heat building over Iberia. It wouldn’t take much for a suitable synoptic to see this heat harnessed for the southern UK.