- Country: US
- State: IL
- Latitude: 42.0
- Longitude: -87.5
High Temperatures
On August 15 in CHICAGO the average high temperature is 77.2 °F (25.1 °C). The lowest recored high temperature was 69.8 °F (21.0 °C) in 2008 and the highest recored high temperature was 86.5 °F (30.3 °C) in 2025. The high temperature is usually* between 73.6 °F (23.1 °C) and 80.8 °F (27.1 °C). About a quarter of the time, the high temperature is less than 73.6 °F (23.1 °C), and another quarter of the time, the high temperature is greater than and 80.8 °F (27.1 °C). About 95% of the time, the high temperature has been between 66.7 °F (19.3 °C) and 87.7 °F (30.9 °C).
Low Temperatures
On August 15 in CHICAGO the average low temperature is 69.9 °F (21.1 °C). The lowest recored low temperature was 61.5 °F (16.4 °C) in 2014 and the lowest recored low temperature was 80.1 °F (26.7 °C) in 2025. The low temperature is usually* between 67.1 °F (19.5 °C) and 72.7 °F (22.6 °C). About a quarter of the time, the low temperature is less than 67.1 °F (19.5 °C), and another quarter of the time, the low temperature is greater than and 72.7 °F (22.6 °C). About 95% of the time, the low temperature has been between 61.8 °F (16.5 °C) and 78.1 °F (25.6 °C).
Frost
On August 15 in CHICAGO expect the temperatures to drop below freezing for a risk of frost about 0.0% 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