Station information
- Integrated Surface Dataset (ISD) station ID: 997338
- Country: US
- State: IL
- Latitude: 42.0
- Longitude: -87.5
High Temperatures
On April 21 in CHICAGO the average high temperature is 55.1 °F (12.9 °C). The lowest recored high temperature was 42.1 °F (5.6 °C) in 2021 and the highest recored high temperature was 73.0 °F (22.8 °C) in 2023. The high temperature is usually* between 47.8 °F (8.8 °C) and 62.4 °F (16.9 °C). About a quarter of the time, the high temperature is less than 47.8 °F (8.8 °C), and another quarter of the time, the high temperature is greater than and 62.4 °F (16.9 °C). About 95% of the time, the high temperature has been between 33.9 °F (1.1 °C) and 76.4 °F (24.6 °C).
Low Temperatures
On April 21 in CHICAGO the average low temperature is 41.9 °F (5.5 °C). The lowest recored low temperature was 35.2 °F (1.8 °C) in 2013 and the lowest recored low temperature was 53.1 °F (11.7 °C) in 2016. The low temperature is usually* between 38.5 °F (3.6 °C) and 45.2 °F (7.3 °C). About a quarter of the time, the low temperature is less than 38.5 °F (3.6 °C), and another quarter of the time, the low temperature is greater than and 45.2 °F (7.3 °C). About 95% of the time, the low temperature has been between 32.2 °F (0.1 °C) and 51.6 °F (10.9 °C).
Frost
On April 21 in CHICAGO expect the temperatures to drop below freezing for a risk of frost about 2.3% 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