- Country: US
- State: IL
- Latitude: 42.0
- Longitude: -87.5
High Temperatures
On May 20 in CHICAGO the average high temperature is 67.5 °F (19.7 °C). The lowest recored high temperature was 42.4 °F (5.8 °C) in 2015 and the highest recored high temperature was 85.3 °F (29.6 °C) in 2024. The high temperature is usually* between 59.5 °F (15.3 °C) and 75.5 °F (24.2 °C). About a quarter of the time, the high temperature is less than 59.5 °F (15.3 °C), and another quarter of the time, the high temperature is greater than and 75.5 °F (24.2 °C). About 95% of the time, the high temperature has been between 44.2 °F (6.8 °C) and 90.8 °F (32.7 °C).
Low Temperatures
On May 20 in CHICAGO the average low temperature is 52.7 °F (11.5 °C). The lowest recored low temperature was 40.5 °F (4.7 °C) in 2007 and the lowest recored low temperature was 66.4 °F (19.1 °C) in 2012. The low temperature is usually* between 47.7 °F (8.7 °C) and 57.6 °F (14.2 °C). About a quarter of the time, the low temperature is less than 47.7 °F (8.7 °C), and another quarter of the time, the low temperature is greater than and 57.6 °F (14.2 °C). About 95% of the time, the low temperature has been between 38.2 °F (3.5 °C) and 67.1 °F (19.5 °C).
Frost
On May 20 in CHICAGO expect the temperatures to drop below freezing for a risk of frost about 0.3% of the time.
Data Source(s)
The data used to compute the average high/low temperatures for this location were taken from the following stations:
- CHICAGO — Integrated Surface Dataset (ISD) station ID: 997338 — from year 2005 to 2025