Station information
- Integrated Surface Dataset (ISD) station ID: 997338
- Country: US
- State: IL
- Latitude: 42.0
- Longitude: -87.5
High Temperatures
On January 21 in CHICAGO the average high temperature is 29.6 °F (-1.3 °C). The lowest recored high temperature was 11.5 °F (-11.4 °C) in 2025 and the highest recored high temperature was 59.5 °F (15.3 °C) in 2017. The high temperature is usually* between 21.9 °F (-5.6 °C) and 37.3 °F (2.9 °C). About a quarter of the time, the high temperature is less than 21.9 °F (-5.6 °C), and another quarter of the time, the high temperature is greater than and 37.3 °F (2.9 °C). About 95% of the time, the high temperature has been between 7.2 °F (-13.8 °C) and 52.0 °F (11.1 °C).
Low Temperatures
On January 21 in CHICAGO the average low temperature is 19.4 °F (-7.0 °C). The lowest recored low temperature was -4.9 °F (-20.5 °C) in 2025 and the lowest recored low temperature was 37.4 °F (3.0 °C) in 2018. The low temperature is usually* between 11.4 °F (-11.4 °C) and 27.4 °F (-2.6 °C). About a quarter of the time, the low temperature is less than 11.4 °F (-11.4 °C), and another quarter of the time, the low temperature is greater than and 27.4 °F (-2.6 °C). About 95% of the time, the low temperature has been between -3.8 °F (-19.9 °C) and 42.6 °F (5.9 °C).
Frost
On January 21 in CHICAGO expect the temperatures to drop below freezing for a risk of frost about 85.6% 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 2007 to 2025