August 18 - Chicago - Weather History and Averages

High Temperatures

On August 18 in Chicago, IL (Illinois), USA the average high temperature is 81.5 °F (27.5 °C). The lowest recored high temperature was 64.0 °F (17.8 °C) in 1950 and the highest recored high temperature was 102.0 °F (38.9 °C) in 1988. The high temperature is usually* between 77.6 °F (25.3 °C) and 85.5 °F (29.7 °C). About a quarter of the time, the high temperature is less than 77.6 °F (25.3 °C), and another quarter of the time, the high temperature is greater than and 85.5 °F (29.7 °C). About 95% of the time, the high temperature has been between 70.0 °F (21.1 °C) and 93.1 °F (33.9 °C).

Low Temperatures

On August 18 in Chicago, IL (Illinois), USA the average low temperature is 64.9 °F (18.3 °C). The lowest recored low temperature was 42.1 °F (5.6 °C) in 1963 and the lowest recored low temperature was 81.0 °F (27.2 °C) in 1988. The low temperature is usually* between 61.2 °F (16.2 °C) and 68.6 °F (20.3 °C). About a quarter of the time, the low temperature is less than 61.2 °F (16.2 °C), and another quarter of the time, the low temperature is greater than and 68.6 °F (20.3 °C). About 95% of the time, the low temperature has been between 54.2 °F (12.3 °C) and 75.6 °F (24.2 °C).

Frost

On August 18 in Chicago, IL (Illinois), USA expect the temperatures to drop below freezing for a risk of frost about 0.0% of the time.

Usually* in this context means around 50% of the time, assuming a normal distribution of values.

Data Source(s)

The data used to compute the average high/low temperatures for this location were taken from the following stations: