So how common are 30+C temperatures in our region?

There have been 135 such days in Coventry since 1892! 

There have been 3 30+C days during May in the past 125 years, 19 in June, 59 in July, 49 in August and 5 during September.

Decade 30C+ days 30-year totals
1892-1900 16 1891-1920 34
1901-1910 7 1901-1930 30
1911-1920 11 1911-1940 28
1921-1930 12 1921-1950 37
1931-1940 5 1931-1960 26
1941-1950 20 1941-1970 23
1951-1960 1 1951-1980 20
1961-1970 2 1961-1990 31
1971-1980 17 1971-2000 47
1981-1990 12 1981-2010 35
1991-2000 18 1991-2020 33 so far
2001-2010 9
2011-2018 6

As you can see, they have been much regular occurrences in the past than since the Millennium!