Station information
- Integrated Surface Dataset (ISD) station ID: 997338
- Country: US
- State: IL
- Latitude: 42.0
- Longitude: -87.5
High Temperatures
On February 18 in CHICAGO the average high temperature is 36.9 °F (2.7 °C). The lowest recored high temperature was 13.3 °F (-10.4 °C) in 2025 and the highest recored high temperature was 64.2 °F (17.9 °C) in 2017. The high temperature is usually* between 27.9 °F (-2.3 °C) and 46.0 °F (7.8 °C). About a quarter of the time, the high temperature is less than 27.9 °F (-2.3 °C), and another quarter of the time, the high temperature is greater than and 46.0 °F (7.8 °C). About 95% of the time, the high temperature has been between 10.5 °F (-11.9 °C) and 63.4 °F (17.4 °C).
Low Temperatures
On February 18 in CHICAGO the average low temperature is 23.6 °F (-4.7 °C). The lowest recored low temperature was -0.6 °F (-18.1 °C) in 2025 and the lowest recored low temperature was 48.7 °F (9.3 °C) in 2017. The low temperature is usually* between 15.8 °F (-9.0 °C) and 31.4 °F (-0.4 °C). About a quarter of the time, the low temperature is less than 15.8 °F (-9.0 °C), and another quarter of the time, the low temperature is greater than and 31.4 °F (-0.4 °C). About 95% of the time, the low temperature has been between 1.1 °F (-17.2 °C) and 46.1 °F (7.8 °C).
Frost
On February 18 in CHICAGO expect the temperatures to drop below freezing for a risk of frost about 76.8% 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