This is a replication of
James Hansen, Makiko Sato, Reto Ruedy (2012): Perception of Climate Change. Proceedings of the National Academy of Sciences, 109(37) E2415-E2423; DOI: 10.1073/pnas.1205276109
and
Andrew Rhines, Peter Huybers (2013): Frequent summer temperature extremes reflect changes in the mean, not the variance, Proceedings of the National Academy of Sciences, 110(7) E546; DOI: 10.1073/pnas.1218748110
was inspired by the New York Times article "It’s Not Your Imagination. Summers Are Getting Hotter".
which features the following visualization:
