April 21 - Chicago - Weather History and Averages

High Temperatures

On April 21 in Chicago, IL (Illinois), USA the average high temperature is 61.7 °F (16.5 °C). The lowest recored high temperature was 42.1 °F (5.6 °C) in 2021 and the highest recored high temperature was 89.1 °F (31.7 °C) in 1987. The high temperature is usually* between 54.6 °F (12.5 °C) and 68.9 °F (20.5 °C). About a quarter of the time, the high temperature is less than 54.6 °F (12.5 °C), and another quarter of the time, the high temperature is greater than and 68.9 °F (20.5 °C). About 95% of the time, the high temperature has been between 40.9 °F (5.0 °C) and 82.6 °F (28.1 °C).

Low Temperatures

On April 21 in Chicago, IL (Illinois), USA the average low temperature is 43.3 °F (6.3 °C). The lowest recored low temperature was 25.2 °F (-3.8 °C) in 1982 and the lowest recored low temperature was 70.0 °F (21.1 °C) in 1985. The low temperature is usually* between 38.2 °F (3.4 °C) and 48.3 °F (9.1 °C). About a quarter of the time, the low temperature is less than 38.2 °F (3.4 °C), and another quarter of the time, the low temperature is greater than and 48.3 °F (9.1 °C). About 95% of the time, the low temperature has been between 28.6 °F (-1.9 °C) and 58.0 °F (14.4 °C).

Frost

On April 21 in Chicago, IL (Illinois), USA expect the temperatures to drop below freezing for a risk of frost about 6.7% 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: