Chicago Heat Waves: A Climatological Comparison

The recent heat waves in Chicago, Illinois in the summer of 2011 and 2012 exhibited well above average temperatures, and had many negative effects on Chicago's citizens. These heat waves were compared from a climatological perspective to those in 1995 and 1999, both of which resulted in significant loss of life. Temperature and derived heat index data from Midway airport in Chicago for each year was examined, and it was found that 2011 was less impressive than 1995 and 1999. The heat wave of 2012 was comparable to 1995 and 1999 when looking at air temperature, but less so when focusing on heat index. Heat index was emphasized as a better measurement for a heat event's impact on human health. There were considerably fewer deaths in 1999 versus 1995, and very few deaths in 2011 and 2012. It would appear the City of Chicago's adaptation techniques following the tragedy of 1995 have been effective in decreasing loss of life. However, with the less intense heat events of 2011 and 2012, it cannot be determined for certain if those adaptation techniques are directly responsible for the considerably lower death toll compared to 1995.