High Temperatures
On July 31 in Chicago, IL (Illinois), USA, the average high temperature is 82.8 °F (28.2 °C). The lowest recored high temperature was 66.4 °F (19.1 °C) in 1947 and the highest recored high temperature was 99.0 °F (37.2 °C) in 2006. The high temperature is usually* between 78.3 °F (25.7 °C) and 87.3 °F (30.7 °C). About a quarter of the time, the high temperature is less than 78.3 °F (25.7 °C), and another quarter of the time, the high temperature is greater than and 87.3 °F (30.7 °C). About 95% of the time, the high temperature has been between 69.8 °F (21.0 °C) and 95.8 °F (35.5 °C).
Low Temperatures
On July 31 in Chicago, IL (Illinois), USA, the average low temperature is 66.5 °F (19.2 °C). The lowest recored low temperature was 50.0 °F (10.0 °C) in 1984 and the lowest recored low temperature was 82.4 °F (28.0 °C) in 1999. The low temperature is usually* between 62.4 °F (16.9 °C) and 70.7 °F (21.5 °C). About a quarter of the time, the low temperature is less than 62.4 °F (16.9 °C), and another quarter of the time, the low temperature is greater than and 70.7 °F (21.5 °C). About 95% of the time, the low temperature has been between 54.5 °F (12.5 °C) and 78.6 °F (25.9 °C).
Frost
On July 31 in Chicago, IL (Illinois), USA, expect the temperatures to drop below freezing for a risk of frost about 0.0% 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:
- NORTHERLY ISLAND — Integrated Surface Dataset (ISD) station ID: 998499 — from year 2012 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
- CHICAGO O'HARE INTERNATIONAL — Integrated Surface Dataset (ISD) station ID: 725300 — Weather Bureau Army Navy (WBAN): 94846 — from year 1947 to 2024
- CHICAGO MIDWAY INTL ARPT — Integrated Surface Dataset (ISD) station ID: 725340 — Weather Bureau Army Navy (WBAN): 14819 — from year 1973 to 2024
- FOSTER AVE CHICAGO — Integrated Surface Dataset (ISD) station ID: 998497 — from year 2012 to 2019
- 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
- NAVAL AIR STATION — Integrated Surface Dataset (ISD) station ID: 725306 — Weather Bureau Army Navy (WBAN): 14855 — from year 1973 to 1994
- WILMETTE (MARINES)& — Integrated Surface Dataset (ISD) station ID: 725307 — from year 1976 to 1994
- CHICAGO / CALUMET COAST GUARD — Integrated Surface Dataset (ISD) station ID: 725344 — from year 1994 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
- NAVAL AIR STATION — Weather Bureau Army Navy (WBAN): 14855 — from year 1945 to 1972
- CHICAGO MIDWAY AP — Weather Bureau Army Navy (WBAN): 14819 — from year 1948 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