Station information
- Integrated Surface Dataset (ISD) station ID: 997338
- Country: US
- State: IL
- Latitude: 42.0
- Longitude: -87.5
High Temperatures
On May 21 in CHICAGO the average high temperature is 68.2 °F (20.1 °C). The lowest recored high temperature was 49.3 °F (9.6 °C) in 2019 and the highest recored high temperature was 85.1 °F (29.5 °C) in 2013. The high temperature is usually* between 60.1 °F (15.6 °C) and 76.2 °F (24.6 °C). About a quarter of the time, the high temperature is less than 60.1 °F (15.6 °C), and another quarter of the time, the high temperature is greater than and 76.2 °F (24.6 °C). About 95% of the time, the high temperature has been between 44.8 °F (7.1 °C) and 91.5 °F (33.1 °C).
Low Temperatures
On May 21 in CHICAGO the average low temperature is 53.4 °F (11.9 °C). The lowest recored low temperature was 41.2 °F (5.1 °C) in 2007 and the lowest recored low temperature was 67.3 °F (19.6 °C) in 2009. The low temperature is usually* between 48.6 °F (9.2 °C) and 58.1 °F (14.5 °C). About a quarter of the time, the low temperature is less than 48.6 °F (9.2 °C), and another quarter of the time, the low temperature is greater than and 58.1 °F (14.5 °C). About 95% of the time, the low temperature has been between 39.5 °F (4.2 °C) and 67.2 °F (19.6 °C).
Frost
On May 21 in CHICAGO expect the temperatures to drop below freezing for a risk of frost about 0.1% 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