- Latitude: 41.8375511
- Longitude: -87.6818441
High Temperatures
On September 21 in Chicago, IL (Illinois), USA the average high temperature is 73.7 °F (23.2 °C). The lowest recored high temperature was 52.0 °F (11.1 °C) in 1995 and the highest recored high temperature was 95.0 °F (35.0 °C) in 2017. The high temperature is usually* between 67.6 °F (19.8 °C) and 79.8 °F (26.5 °C). About a quarter of the time, the high temperature is less than 67.6 °F (19.8 °C), and another quarter of the time, the high temperature is greater than and 79.8 °F (26.5 °C). About 95% of the time, the high temperature has been between 56.1 °F (13.4 °C) and 91.3 °F (33.0 °C).
Low Temperatures
On September 21 in Chicago, IL (Illinois), USA the average low temperature is 56.7 °F (13.7 °C). The lowest recored low temperature was 33.1 °F (0.6 °C) in 1962 and the lowest recored low temperature was 75.9 °F (24.4 °C) in 1970. The low temperature is usually* between 51.0 °F (10.5 °C) and 62.4 °F (16.9 °C). About a quarter of the time, the low temperature is less than 51.0 °F (10.5 °C), and another quarter of the time, the low temperature is greater than and 62.4 °F (16.9 °C). About 95% of the time, the low temperature has been between 40.2 °F (4.5 °C) and 73.2 °F (22.9 °C).
Frost
On September 21 in Chicago, IL (Illinois), USA expect the temperatures to drop below freezing for a risk of frost about 0.2% 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 MIDWAY INTL ARPT — Integrated Surface Dataset (ISD) station ID: 725340 — Weather Bureau Army Navy (WBAN): 14819 — from year 1973 to 2024
- GARY/CHICAGO AIRPORT — Integrated Surface Dataset (ISD) station ID: 725337 — Weather Bureau Army Navy (WBAN): 04807 — from year 2006 to 2024
- CHICAGO O'HARE INTERNATIONAL — Integrated Surface Dataset (ISD) station ID: 725300 — Weather Bureau Army Navy (WBAN): 94846 — from year 1947 to 2024
- 9087044 - CALUMET IL — Integrated Surface Dataset (ISD) station ID: 997255 — from year 2005 to 2024
- CHICAGO — Integrated Surface Dataset (ISD) station ID: 997338 — from year 2005 to 2024
- NORTHERLY ISLAND — Integrated Surface Dataset (ISD) station ID: 998499 — from year 2012 to 2024
- FOSTER AVE CHICAGO — Integrated Surface Dataset (ISD) station ID: 998497 — from year 2012 to 2017
-
— Integrated Surface Dataset (ISD) station ID: 725337 — from year 1981 to 2005 - CHICAGO/MEIGS — Integrated Surface Dataset (ISD) station ID: 725346 — from year 2000 to 2002
- CHICAGO/MEIGS — Integrated Surface Dataset (ISD) station ID: 725346 — Weather Bureau Army Navy (WBAN): 94866 — from year 1973 to 1999
- CHICAGO / CALUMET COAST GUARD — Integrated Surface Dataset (ISD) station ID: 725344 — from year 1995 to 1995
- WILMETTE (MARINES)& — Integrated Surface Dataset (ISD) station ID: 725307 — from year 1976 to 1995
- NAVAL AIR STATION — Integrated Surface Dataset (ISD) station ID: 725306 — Weather Bureau Army Navy (WBAN): 14855 — from year 1973 to 1994
- WILMETTE (CGS) — Integrated Surface Dataset (ISD) station ID: 722417 — from year 1987 to 1990
- CALUMET (CGS) — Integrated Surface Dataset (ISD) station ID: 722418 — from year 1987 to 1989
- CHICAGO OHARE INTL AP — Weather Bureau Army Navy (WBAN): 94846 — from year 1970 to 1972
- CHICAGO MIDWAY AP — Weather Bureau Army Navy (WBAN): 14819 — from year 1948 to 1972
- NAVAL AIR STATION — Weather Bureau Army Navy (WBAN): 14855 — from year 1945 to 1972
- CHICAGO MEIGS FIELD — Weather Bureau Army Navy (WBAN): 94866 — from year 1966 to 1969
- PARK RIDGE AF — Weather Bureau Army Navy (WBAN): 14810 — from year 1949 to 1958