July 21 - Chicago - Weather History and Averages

High Temperatures

On July 21 in Chicago, IL (Illinois), USA the average high temperature is 83.9 °F (28.9 °C). The lowest recored high temperature was 66.0 °F (18.9 °C) in 1947 and the highest recored high temperature was 100.9 °F (38.3 °C) in 2011. The high temperature is usually* between 79.3 °F (26.3 °C) and 88.6 °F (31.4 °C). About a quarter of the time, the high temperature is less than 79.3 °F (26.3 °C), and another quarter of the time, the high temperature is greater than and 88.6 °F (31.4 °C). About 95% of the time, the high temperature has been between 70.5 °F (21.4 °C) and 97.3 °F (36.3 °C).

Low Temperatures

On July 21 in Chicago, IL (Illinois), USA the average low temperature is 67.4 °F (19.7 °C). The lowest recored low temperature was 48.0 °F (8.9 °C) in 1966 and the lowest recored low temperature was 87.3 °F (30.7 °C) in 2022. The low temperature is usually* between 63.7 °F (17.6 °C) and 71.1 °F (21.7 °C). About a quarter of the time, the low temperature is less than 63.7 °F (17.6 °C), and another quarter of the time, the low temperature is greater than and 71.1 °F (21.7 °C). About 95% of the time, the low temperature has been between 56.6 °F (13.7 °C) and 78.2 °F (25.6 °C).

Frost

On July 21 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: