On June 16th, 1970, Mungo Jerry were at No.1 on the UK singles chart with ‘In The Summertime’.
It went on to become the best selling UK single of 1970 spending seven weeks at No.1 and was a hit in 26 other countries. The UK release was a maxi-single playing at 33 rpm, (whereas singles generally played at 45 rpm).
Source: This Day in Music