What was London’s average maximum summer temperature in the early 1970s? [origin

Summer temperatures in London have risen more over the last 30 years than in any other European capital city, according to a new report. The study shows that London’s average maximum summer temperature has jumped from 20.5OC in the early 1970s, to 22.5OC over the last five years, a rise of two degrees. Across the 16 capital cities, 13 have risen by at least 1℃ over the last 30 years. The report by environmental group WWF, says that climate change will increase the likelihood of more frequent and intense heat waves, droughts and rainstorms.