I have calculated the summer index rating for Summer 2004 in Manchester. Summer 2004 had a rating of 196, the lowest value since 1998 which had a value of 192. The high mean temperatures of June and August saved the summer from having a lower index rating. The rating for an average summer in Manchester is 212. The highest rating was 301 for summer 1976 The lowest rating was 143 for summer 1954