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