Chicago - Hottest Decades

Ranked here are the hottest decades on record for Chicago, Illinois. The lists include decades when Chicago had the highest average temperatures, the most hot days and the fewest cold days. These extremes are for temperatures observed at Chicago's Midway Airport and cover eight decades, from the 1940s to the 2010s.

That is when Chicago had weather measurements that are consistent and complete enough to compare decades. Each decade comprises a standard 10-year range. For instance, the 1990s includes measurements from Jan 1, 1990 to Dec 31, 1999. Links to the data behind these lists are in the References section on this page.

Hottest High Temperatures

Average daily maximum temperature at Chicago
High °F Decade High °C
Highest 60.4 2010s 15.8
Runner-up 60.2 1990s 15.7

Warmest Low Temperatures

Average daily minimum temperature at Chicago
Low °F Decade Low °C
Highest 44.3 2010s 6.8
Runner-up 43.8 1990s 6.6

Most Warm Days

Total days per year on average when Chicago had temperatures of at least 70 °F (21 °C)
Days Decade
Highest 149 2010s, 1950s
Runner-up 145 1960s

Most Hot Days

Total days per year on average when Chicago had temperatures of at least 90 °F (32 °C)
Days Decade
Highest 28 1950s
Runner-up 24 1940s

Fewest Freezing Days

Total days per year on average when Chicago had temperatures of 32 °F (0 °C) or lower
Days Decade
Lowest 108 2010s, 2000s, 1990s
Runner-up 118 1980s

Fewest Cold Days

Total days per year on average when Chicago had temperatures of 0 °F (-18 °C) or lower
Days Decade
Lowest 4 2000s, 1990s
Runner-up 5 2010s

How Much Hotter are 2010s?

Compared with averages for the previous 50 years (1960 to 2009), the 2010s in Chicago had:

  • 5 more days each year with temperatures of 70 °F and higher
  • 0.9 °F higher daily maximum temperatures (0.5 °C)
  • 1.7 °F higher daily minimum temperatures (0.9 °C)
  • 7 fewer days a year with freezing temperatures
References

Current Results. 2020. Chicago IL Temperature Averages by Decade

Jay Lawrimore, Ron Ray, Scott Applequist, Bryant Korzeniewski, Matthew Menne. 2016. Global Summary of the Year, Version 1.0. NOAA National Centers for Environmental Information.

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