Chicago Ohare Intl AP Weather Records (USW00094846)
Record envelope, standing records and threshold days for Chicago Ohare Intl AP (USW00094846), Illinois, United States, with 69 years of record.
Key Facts for Chicago Ohare Intl AP
- Chicago Ohare Intl AP (USW00094846) is a weather station in Illinois, United States at 41.96 latitude and -87.93 longitude, 205 m (672 ft) above sea level.
- The station reports from 1958 to 2026, 69 years of record.
- 1,464 records set at Chicago Ohare Intl AP still stand.
- Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
- Chicago Ohare Intl AP set a daily record high minimum temperature of 18.3 C (64.9 F) on 13 October 2026 (provisional).
Provisional Records
Records set in the last 60 days are provisional until they clear the revision window.
About the Station
- Location: Illinois, United States, 41.96 latitude, -87.93 longitude.
- Elevation: 205 m (672 ft).
- Period of record: 1958 to 2026, 69 years.
- Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
9 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 18.3 C (64.9 F) | -32.8 C (-27.0 F) | 15.6 C (60.1 F) | -23.9 C (-11.0 F) |
| Feb | 23.3 C (73.9 F) | -28.3 C (-18.9 F) | 18.3 C (64.9 F) | -13.9 C (7.0 F) |
| Mar | 31.1 C (88.0 F) | -22.2 C (-8.0 F) | 27.2 C (81.0 F) | -10.0 C (14.0 F) |
| Apr | 32.8 C (91.0 F) | -13.9 C (7.0 F) | 27.8 C (82.0 F) | -2.2 C (28.0 F) |
| May | 36.1 C (97.0 F) | -4.4 C (24.1 F) | 30.6 C (87.1 F) | 0.0 C (32.0 F) |
| Jun | 40.0 C (104.0 F) | 2.2 C (36.0 F) | 34.4 C (93.9 F) | 10.0 C (50.0 F) |
| Jul | 40.0 C (104.0 F) | 4.4 C (39.9 F) | 35.6 C (96.1 F) | 14.4 C (57.9 F) |
| Aug | 38.3 C (100.9 F) | 5.0 C (41.0 F) | 30.6 C (87.1 F) | 14.4 C (57.9 F) |
| Sep | 37.2 C (99.0 F) | -2.2 C (28.0 F) | 35.6 C (96.1 F) | 9.4 C (48.9 F) |
| Oct | 32.8 C (91.0 F) | -8.3 C (17.1 F) | 31.1 C (88.0 F) | 8.3 C (46.9 F) |
| Nov | 25.6 C (78.1 F) | -17.2 C (1.0 F) | n/a | n/a |
| Dec | 21.7 C (71.1 F) | -31.7 C (-25.1 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1958 | 12 |
| 1959 | 31 |
| 1960 | 23 |
| 1961 | 16 |
| 1962 | 35 |
| 1963 | 57 |
| 1964 | 40 |
| 1965 | 39 |
| 1966 | 33 |
| 1967 | 41 |
| 1968 | 22 |
| 1969 | 7 |
| 1970 | 18 |
| 1971 | 22 |
| 1972 | 26 |
| 1973 | 21 |
| 1974 | 22 |
| 1975 | 17 |
| 1976 | 19 |
| 1977 | 27 |
| 1978 | 7 |
| 1979 | 31 |
| 1980 | 23 |
| 1981 | 21 |
| 1982 | 37 |
| 1983 | 42 |
| 1984 | 23 |
| 1985 | 26 |
| 1986 | 22 |
| 1987 | 13 |
| 1988 | 35 |
| 1989 | 20 |
| 1990 | 26 |
| 1991 | 35 |
| 1992 | 27 |
| 1993 | 17 |
| 1994 | 21 |
| 1995 | 15 |
| 1996 | 20 |
| 1997 | 14 |
| 1998 | 17 |
| 1999 | 10 |
| 2000 | 20 |
| 2001 | 11 |
| 2002 | 17 |
| 2003 | 8 |
| 2004 | 9 |
| 2005 | 14 |
| 2006 | 23 |
| 2007 | 13 |
| 2008 | 13 |
| 2009 | 13 |
| 2010 | 7 |
| 2011 | 13 |
| 2012 | 43 |
| 2013 | 11 |
| 2014 | 19 |
| 2015 | 15 |
| 2016 | 10 |
| 2017 | 36 |
| 2018 | 15 |
| 2019 | 14 |
| 2020 | 13 |
| 2021 | 19 |
| 2022 | 18 |
| 2023 | 12 |
| 2024 | 20 |
| 2025 | 17 |
| 2026 | 11 |
All-Time Record Progression
4 new records| Date | Kind | Detail |
|---|---|---|
| 1995-07-14 | Record high minimum temperature | Record high minimum temperature 28.3 C (82.9 F) |
| 1999-01-02 | Record daily snowfall | Record daily snowfall 47.2 cm (18.6 in) |
| 2008-09-13 | Record daily precipitation | Record daily precipitation 168.7 mm (6.6 in) |
| 2011-07-23 | Record daily precipitation | Record daily precipitation 174.2 mm (6.9 in) |
Wettest Day of Each Month
Jul: 174.2 mm (6.9 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 50.8 mm (2.0 in) | 12 January 1960 |
| Feb | 87.4 mm (3.4 in) | 21 February 1997 |
| Mar | 46.7 mm (1.8 in) | 30 March 2017 |
| Apr | 89.9 mm (3.5 in) | 18 April 2013 |
| May | 89.7 mm (3.5 in) | 14 May 2020 |
| Jun | 100.8 mm (4.0 in) | 19 June 2009 |
| Jul | 174.2 mm (6.9 in) | 23 July 2011 |
| Aug | 164.8 mm (6.5 in) | 14 August 1987 |
| Sep | 168.7 mm (6.6 in) | 13 September 2008 |
| Oct | 108.0 mm (4.3 in) | 10 October 1969 |
| Nov | 74.4 mm (2.9 in) | 27 November 1990 |
| Dec | 113.5 mm (4.5 in) | 2 December 1982 |
Period of Record Coverage
1958 to 2026| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1958 | 61 | 17% | No |
| 1959 | 365 | 100% | Yes |
| 1960 | 366 | 100% | Yes |
| 1961 | 365 | 100% | Yes |
| 1962 | 365 | 100% | Yes |
| 1963 | 365 | 100% | Yes |
| 1964 | 366 | 100% | Yes |
| 1965 | 365 | 100% | Yes |
| 1966 | 365 | 100% | Yes |
| 1967 | 365 | 100% | Yes |
| 1968 | 366 | 100% | Yes |
| 1969 | 365 | 100% | Yes |
| 1970 | 365 | 100% | Yes |
| 1971 | 365 | 100% | Yes |
| 1972 | 366 | 100% | Yes |
| 1973 | 365 | 100% | Yes |
| 1974 | 365 | 100% | Yes |
| 1975 | 365 | 100% | Yes |
| 1976 | 366 | 100% | Yes |
| 1977 | 365 | 100% | Yes |
| 1978 | 365 | 100% | Yes |
| 1979 | 365 | 100% | Yes |
| 1980 | 366 | 100% | Yes |
| 1981 | 365 | 100% | Yes |
| 1982 | 365 | 100% | Yes |
| 1983 | 365 | 100% | Yes |
| 1984 | 366 | 100% | Yes |
| 1985 | 365 | 100% | Yes |
| 1986 | 365 | 100% | Yes |
| 1987 | 365 | 100% | Yes |
| 1988 | 366 | 100% | Yes |
| 1989 | 365 | 100% | Yes |
| 1990 | 365 | 100% | Yes |
| 1991 | 365 | 100% | Yes |
| 1992 | 366 | 100% | Yes |
| 1993 | 365 | 100% | Yes |
| 1994 | 365 | 100% | Yes |
| 1995 | 365 | 100% | Yes |
| 1996 | 366 | 100% | Yes |
| 1997 | 365 | 100% | Yes |
| 1998 | 365 | 100% | Yes |
| 1999 | 365 | 100% | Yes |
| 2000 | 366 | 100% | Yes |
| 2001 | 365 | 100% | Yes |
| 2002 | 365 | 100% | Yes |
| 2003 | 365 | 100% | Yes |
| 2004 | 366 | 100% | Yes |
| 2005 | 365 | 100% | Yes |
| 2006 | 365 | 100% | Yes |
| 2007 | 365 | 100% | Yes |
| 2008 | 366 | 100% | Yes |
| 2009 | 365 | 100% | Yes |
| 2010 | 365 | 100% | Yes |
| 2011 | 365 | 100% | Yes |
| 2012 | 366 | 100% | Yes |
| 2013 | 365 | 100% | Yes |
| 2014 | 365 | 100% | Yes |
| 2015 | 365 | 100% | Yes |
| 2016 | 366 | 100% | Yes |
| 2017 | 365 | 100% | Yes |
| 2018 | 365 | 100% | Yes |
| 2019 | 365 | 100% | Yes |
| 2020 | 366 | 100% | Yes |
| 2021 | 365 | 100% | Yes |
| 2022 | 365 | 100% | Yes |
| 2023 | 365 | 100% | Yes |
| 2024 | 366 | 100% | Yes |
| 2025 | 365 | 100% | Yes |
| 2026 | 286 | 78% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 13 October 2026 | Chicago Ohare Intl AP, US | daily high min (Provisional) | 18.3 C (64.9 F) | 0.5 C (0.9 F) | 51 years | 21 of 100 (Routine) |
| 12 October 2026 | Chicago Ohare Intl AP, US | daily high min (Provisional) | 17.2 C (63.0 F) | 1.1 C (2.0 F) | 52 years | 23 of 100 (Routine) |
| 12 October 2026 | Chicago Ohare Intl AP, US | daily high max (Provisional) | 31.1 C (88.0 F) | 2.2 C (4.0 F) | 17 years | 14 of 100 (Routine) |
| 9 September 2026 | Chicago Ohare Intl AP, US | daily high min (Provisional) | 21.7 C (71.1 F) | 0.6 C (1.1 F) | 43 years | 19 of 100 (Routine) |
| 4 September 2026 | Chicago Ohare Intl AP, US | daily high min (Provisional) | 24.4 C (75.9 F) | 1.1 C (2.0 F) | 55 years | 24 of 100 (Routine) |
| 3 September 2026 | Chicago Ohare Intl AP, US | daily high min (Provisional) | 25.0 C (77.0 F) | 2.2 C (4.0 F) | 55 years | 26 of 100 (Routine) |
| 2 September 2026 | Chicago Ohare Intl AP, US | monthly high min (Provisional) | 25.6 C (78.1 F) | 0.6 C (1.1 F) | 12 years | 20 of 100 (Routine) |
| 2 September 2026 | Chicago Ohare Intl AP, US | daily high max (Provisional) | 35.6 C (96.1 F) | 1.2 C (2.2 F) | 17 years | 13 of 100 (Routine) |
| 1 September 2026 | Chicago Ohare Intl AP, US | monthly high min (Tie, Provisional) | 25.0 C (77.0 F) | tie | 12 years | 4 of 100 (Routine) |
| 31 August 2026 | Chicago Ohare Intl AP, US | daily rain (Provisional) | 16.5 mm (0.6 in) | 5.3 mm (0.21 in) | 45 years | 20 of 100 (Routine) |
| 27 July 2026 | Chicago Ohare Intl AP, US | daily rain | 44.7 mm (1.8 in) | 26.7 mm (1.1 in) | 15 years | 28 of 100 (Routine) |
| 16 July 2026 | Chicago Ohare Intl AP, US | daily high min (Tie) | 23.9 C (75.0 F) | tie | 44 years | 4 of 100 (Routine) |
| 3 July 2026 | Chicago Ohare Intl AP, US | daily rain | 43.4 mm (1.7 in) | 9.9 mm (0.39 in) | 21 years | 18 of 100 (Routine) |
| 1 July 2026 | Chicago Ohare Intl AP, US | daily high min | 26.7 C (80.1 F) | 2.3 C (4.1 F) | 56 years | 28 of 100 (Routine) |
| 30 June 2026 | Chicago Ohare Intl AP, US | daily high max (Tie) | 34.4 C (93.9 F) | tie | 29 years | 3 of 100 (Routine) |
| 29 June 2026 | Chicago Ohare Intl AP, US | daily high min | 24.4 C (75.9 F) | 1.6 C (2.9 F) | 55 years | 25 of 100 (Routine) |
| 5 June 2026 | Chicago Ohare Intl AP, US | daily high min (Tie) | 21.1 C (70.0 F) | tie | 5 years | 1 of 100 (Routine) |
| 14 April 2026 | Chicago Ohare Intl AP, US | daily rain | 61.7 mm (2.4 in) | 36.0 mm (1.4 in) | 39 years | 52 of 100 (Notable) |
| 13 April 2026 | Chicago Ohare Intl AP, US | daily high min | 16.7 C (62.1 F) | 2.3 C (4.1 F) | 57 years | 27 of 100 (Routine) |
| 30 March 2026 | Chicago Ohare Intl AP, US | daily high max | 27.2 C (81.0 F) | 1.1 C (2.0 F) | 59 years | 24 of 100 (Routine) |
Climate Trend
67 complete years, 1959 to 2025| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1959 | 9.7 C | -0.26 C |
| 1960 | 9.3 C | -0.64 C |
| 1961 | 9.1 C | -0.83 C |
| 1962 | 8.9 C | -1.03 C |
| 1963 | 8.4 C | -1.57 C |
| 1964 | 9.3 C | -0.62 C |
| 1965 | 8.9 C | -1.11 C |
| 1966 | 8.9 C | -1.06 C |
| 1967 | 8.7 C | -1.23 C |
| 1968 | 10.1 C | +0.18 C |
| 1969 | 9.6 C | -0.37 C |
| 1970 | 10.0 C | +0.02 C |
| 1971 | 10.6 C | +0.59 C |
| 1972 | 8.6 C | -1.34 C |
| 1973 | 10.8 C | +0.85 C |
| 1974 | 9.7 C | -0.30 C |
| 1975 | 10.5 C | +0.54 C |
| 1976 | 9.2 C | -0.73 C |
| 1977 | 10.2 C | +0.26 C |
| 1978 | 8.5 C | -1.42 C |
| 1979 | 8.9 C | -1.10 C |
| 1980 | 9.2 C | -0.76 C |
| 1981 | 9.3 C | -0.65 C |
| 1982 | 8.7 C | -1.23 C |
| 1983 | 9.4 C | -0.56 C |
| 1984 | 9.1 C | -0.90 C |
| 1985 | 8.3 C | -1.65 C |
| 1986 | 9.8 C | -0.20 C |
| 1987 | 11.1 C | +1.13 C |
| 1988 | 9.8 C | -0.13 C |
| 1989 | 8.9 C | -1.03 C |
| 1990 | 10.8 C | +0.79 C |
| 1991 | 10.6 C | +0.64 C |
| 1992 | 9.2 C | -0.76 C |
| 1993 | 9.1 C | -0.87 C |
| 1994 | 9.9 C | -0.03 C |
| 1995 | 10.0 C | +0.02 C |
| 1996 | 8.5 C | -1.50 C |
| 1997 | 9.1 C | -0.83 C |
| 1998 | 11.9 C | +1.96 C |
| 1999 | 10.6 C | +0.67 C |
| 2000 | 9.9 C | -0.09 C |
| 2001 | 10.4 C | +0.41 C |
| 2002 | 10.5 C | +0.49 C |
| 2003 | 9.4 C | -0.61 C |
| 2004 | 9.9 C | -0.05 C |
| 2005 | 10.7 C | +0.71 C |
| 2006 | 11.0 C | +1.06 C |
| 2007 | 10.6 C | +0.64 C |
| 2008 | 9.3 C | -0.67 C |
| 2009 | 9.3 C | -0.69 C |
| 2010 | 10.8 C | +0.83 C |
| 2011 | 10.4 C | +0.41 C |
| 2012 | 12.5 C | +2.50 C |
| 2013 | 9.5 C | -0.46 C |
| 2014 | 8.6 C | -1.32 C |
| 2015 | 10.1 C | +0.09 C |
| 2016 | 11.3 C | +1.30 C |
| 2017 | 11.4 C | +1.46 C |
| 2018 | 10.5 C | +0.58 C |
| 2019 | 9.8 C | -0.14 C |
| 2020 | 11.8 C | +1.87 C |
| 2021 | 11.9 C | +1.90 C |
| 2022 | 10.7 C | +0.76 C |
| 2023 | 12.3 C | +2.29 C |
| 2024 | 12.8 C | +2.81 C |
| 2025 | 11.2 C | +1.21 C |
The annual mean temperature here has risen by 0.3 C (0.2 to 0.4) per decade over 1959 to 2025. In Fahrenheit: 0.6 F (0.4 to 0.8) per decade. The slope is a straight line fitted to 67 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.3 C (0.2 to 0.4) per decade | 0.6 F (0.4 to 0.8) per decade | 1959 to 2025 | 67 | Rise |
| Mean daily maximum | 0.2 C (0.1 to 0.3) per decade | 0.4 F (0.2 to 0.6) per decade | 1959 to 2025 | 67 | Rise |
| Mean daily minimum | 0.4 C (0.3 to 0.5) per decade | 0.8 F (0.5 to 1.0) per decade | 1959 to 2025 | 67 | Rise |
A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.
Extremes by Year
1958 to 2026| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 40.0 C (104.0 F) | 1988 | 35.6 C (96.1 F) | 69 |
| Coldest night (TNn) | -32.8 C (-27.0 F) | 1985 | -23.3 C (-9.9 F) | 69 |
| Wettest day (Rx1day) | 174.2 mm (6.9 in) | 2011 | 61.7 mm (2.4 in) | 69 |
| Wettest five days (Rx5day) | 326.1 mm (12.8 in) | 1987 | 95.0 mm (3.7 in) | 69 |
| Longest dry spell (CDD) | 32 days | 1979 | 18 days | 69 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1958 | 21.7 C (71.1 F) |
| 1959 | 36.1 C (97.0 F) |
| 1960 | 37.2 C (99.0 F) |
| 1961 | 33.9 C (93.0 F) |
| 1962 | 34.4 C (93.9 F) |
| 1963 | 35.0 C (95.0 F) |
| 1964 | 35.6 C (96.1 F) |
| 1965 | 34.4 C (93.9 F) |
| 1966 | 36.1 C (97.0 F) |
| 1967 | 33.3 C (91.9 F) |
| 1968 | 35.6 C (96.1 F) |
| 1969 | 35.6 C (96.1 F) |
| 1970 | 35.0 C (95.0 F) |
| 1971 | 36.1 C (97.0 F) |
| 1972 | 33.9 C (93.0 F) |
| 1973 | 35.0 C (95.0 F) |
| 1974 | 36.1 C (97.0 F) |
| 1975 | 34.4 C (93.9 F) |
| 1976 | 36.7 C (98.1 F) |
| 1977 | 36.7 C (98.1 F) |
| 1978 | 35.0 C (95.0 F) |
| 1979 | 34.4 C (93.9 F) |
| 1980 | 38.9 C (102.0 F) |
| 1981 | 35.6 C (96.1 F) |
| 1982 | 35.0 C (95.0 F) |
| 1983 | 37.8 C (100.0 F) |
| 1984 | 37.2 C (99.0 F) |
| 1985 | 37.2 C (99.0 F) |
| 1986 | 35.0 C (95.0 F) |
| 1987 | 37.2 C (99.0 F) |
| 1988 | 40.0 C (104.0 F) |
| 1989 | 38.3 C (100.9 F) |
| 1990 | 35.6 C (96.1 F) |
| 1991 | 38.3 C (100.9 F) |
| 1992 | 33.9 C (93.0 F) |
| 1993 | 34.4 C (93.9 F) |
| 1994 | 35.0 C (95.0 F) |
| 1995 | 40.0 C (104.0 F) |
| 1996 | 34.4 C (93.9 F) |
| 1997 | 36.1 C (97.0 F) |
| 1998 | 35.0 C (95.0 F) |
| 1999 | 38.3 C (100.9 F) |
| 2000 | 33.9 C (93.0 F) |
| 2001 | 35.0 C (95.0 F) |
| 2002 | 35.6 C (96.1 F) |
| 2003 | 35.0 C (95.0 F) |
| 2004 | 32.8 C (91.0 F) |
| 2005 | 38.9 C (102.0 F) |
| 2006 | 37.2 C (99.0 F) |
| 2007 | 34.4 C (93.9 F) |
| 2008 | 34.4 C (93.9 F) |
| 2009 | 34.4 C (93.9 F) |
| 2010 | 34.4 C (93.9 F) |
| 2011 | 37.2 C (99.0 F) |
| 2012 | 39.4 C (102.9 F) |
| 2013 | 35.6 C (96.1 F) |
| 2014 | 32.8 C (91.0 F) |
| 2015 | 33.3 C (91.9 F) |
| 2016 | 33.9 C (93.0 F) |
| 2017 | 35.0 C (95.0 F) |
| 2018 | 36.1 C (97.0 F) |
| 2019 | 35.0 C (95.0 F) |
| 2020 | 36.1 C (97.0 F) |
| 2021 | 35.0 C (95.0 F) |
| 2022 | 37.2 C (99.0 F) |
| 2023 | 37.8 C (100.0 F) |
| 2024 | 37.2 C (99.0 F) |
| 2025 | 35.0 C (95.0 F) |
| 2026 | 35.6 C (96.1 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1958 | -25.6 C (-14.1 F) |
| 1959 | -25.0 C (-13.0 F) |
| 1960 | -27.2 C (-17.0 F) |
| 1961 | -22.2 C (-8.0 F) |
| 1962 | -26.1 C (-15.0 F) |
| 1963 | -28.3 C (-18.9 F) |
| 1964 | -25.0 C (-13.0 F) |
| 1965 | -25.6 C (-14.1 F) |
| 1966 | -28.9 C (-20.0 F) |
| 1967 | -27.2 C (-17.0 F) |
| 1968 | -25.0 C (-13.0 F) |
| 1969 | -22.2 C (-8.0 F) |
| 1970 | -26.1 C (-15.0 F) |
| 1971 | -23.3 C (-9.9 F) |
| 1972 | -27.2 C (-17.0 F) |
| 1973 | -17.8 C (0.0 F) |
| 1974 | -25.0 C (-13.0 F) |
| 1975 | -21.7 C (-7.1 F) |
| 1976 | -25.0 C (-13.0 F) |
| 1977 | -27.2 C (-17.0 F) |
| 1978 | -23.3 C (-9.9 F) |
| 1979 | -27.2 C (-17.0 F) |
| 1980 | -22.2 C (-8.0 F) |
| 1981 | -23.9 C (-11.0 F) |
| 1982 | -32.2 C (-26.0 F) |
| 1983 | -31.7 C (-25.1 F) |
| 1984 | -30.0 C (-22.0 F) |
| 1985 | -32.8 C (-27.0 F) |
| 1986 | -22.8 C (-9.0 F) |
| 1987 | -20.6 C (-5.1 F) |
| 1988 | -25.6 C (-14.1 F) |
| 1989 | -25.6 C (-14.1 F) |
| 1990 | -21.1 C (-6.0 F) |
| 1991 | -19.4 C (-2.9 F) |
| 1992 | -24.4 C (-11.9 F) |
| 1993 | -20.6 C (-5.1 F) |
| 1994 | -29.4 C (-20.9 F) |
| 1995 | -20.0 C (-4.0 F) |
| 1996 | -28.3 C (-18.9 F) |
| 1997 | -22.8 C (-9.0 F) |
| 1998 | -18.3 C (-0.9 F) |
| 1999 | -26.7 C (-16.1 F) |
| 2000 | -22.8 C (-9.0 F) |
| 2001 | -18.9 C (-2.0 F) |
| 2002 | -21.7 C (-7.1 F) |
| 2003 | -21.7 C (-7.1 F) |
| 2004 | -22.8 C (-9.0 F) |
| 2005 | -18.3 C (-0.9 F) |
| 2006 | -21.7 C (-7.1 F) |
| 2007 | -23.3 C (-9.9 F) |
| 2008 | -21.1 C (-6.0 F) |
| 2009 | -27.8 C (-18.0 F) |
| 2010 | -18.3 C (-0.9 F) |
| 2011 | -22.8 C (-9.0 F) |
| 2012 | -15.0 C (5.0 F) |
| 2013 | -21.0 C (-5.8 F) |
| 2014 | -26.6 C (-15.9 F) |
| 2015 | -23.2 C (-9.8 F) |
| 2016 | -24.9 C (-12.8 F) |
| 2017 | -19.9 C (-3.8 F) |
| 2018 | -22.7 C (-8.9 F) |
| 2019 | -30.5 C (-22.9 F) |
| 2020 | -18.8 C (-1.8 F) |
| 2021 | -21.6 C (-6.9 F) |
| 2022 | -22.1 C (-7.8 F) |
| 2023 | -18.2 C (-0.8 F) |
| 2024 | -23.2 C (-9.8 F) |
| 2025 | -22.1 C (-7.8 F) |
| 2026 | -23.9 C (-11.0 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1958 | 16.5 mm (0.6 in) |
| 1959 | 33.8 mm (1.3 in) |
| 1960 | 50.8 mm (2.0 in) |
| 1961 | 73.2 mm (2.9 in) |
| 1962 | 72.1 mm (2.8 in) |
| 1963 | 50.3 mm (2.0 in) |
| 1964 | 59.2 mm (2.3 in) |
| 1965 | 45.0 mm (1.8 in) |
| 1966 | 68.3 mm (2.7 in) |
| 1967 | 78.5 mm (3.1 in) |
| 1968 | 87.1 mm (3.4 in) |
| 1969 | 108.0 mm (4.3 in) |
| 1970 | 53.6 mm (2.1 in) |
| 1971 | 58.4 mm (2.3 in) |
| 1972 | 64.8 mm (2.6 in) |
| 1973 | 51.6 mm (2.0 in) |
| 1974 | 40.1 mm (1.6 in) |
| 1975 | 88.4 mm (3.5 in) |
| 1976 | 53.1 mm (2.1 in) |
| 1977 | 48.8 mm (1.9 in) |
| 1978 | 71.9 mm (2.8 in) |
| 1979 | 56.9 mm (2.2 in) |
| 1980 | 49.8 mm (2.0 in) |
| 1981 | 87.6 mm (3.4 in) |
| 1982 | 113.5 mm (4.5 in) |
| 1983 | 71.4 mm (2.8 in) |
| 1984 | 42.7 mm (1.7 in) |
| 1985 | 69.6 mm (2.7 in) |
| 1986 | 45.2 mm (1.8 in) |
| 1987 | 164.8 mm (6.5 in) |
| 1988 | 91.7 mm (3.6 in) |
| 1989 | 88.1 mm (3.5 in) |
| 1990 | 79.8 mm (3.1 in) |
| 1991 | 65.3 mm (2.6 in) |
| 1992 | 41.7 mm (1.6 in) |
| 1993 | 73.7 mm (2.9 in) |
| 1994 | 68.3 mm (2.7 in) |
| 1995 | 60.2 mm (2.4 in) |
| 1996 | 53.3 mm (2.1 in) |
| 1997 | 87.4 mm (3.4 in) |
| 1998 | 68.3 mm (2.7 in) |
| 1999 | 49.8 mm (2.0 in) |
| 2000 | 60.2 mm (2.4 in) |
| 2001 | 109.5 mm (4.3 in) |
| 2002 | 113.0 mm (4.4 in) |
| 2003 | 56.9 mm (2.2 in) |
| 2004 | 37.8 mm (1.5 in) |
| 2005 | 34.3 mm (1.4 in) |
| 2006 | 52.1 mm (2.1 in) |
| 2007 | 59.7 mm (2.4 in) |
| 2008 | 168.7 mm (6.6 in) |
| 2009 | 100.8 mm (4.0 in) |
| 2010 | 92.5 mm (3.6 in) |
| 2011 | 174.2 mm (6.9 in) |
| 2012 | 34.0 mm (1.3 in) |
| 2013 | 89.9 mm (3.5 in) |
| 2014 | 70.1 mm (2.8 in) |
| 2015 | 65.0 mm (2.6 in) |
| 2016 | 40.6 mm (1.6 in) |
| 2017 | 106.4 mm (4.2 in) |
| 2018 | 59.9 mm (2.4 in) |
| 2019 | 57.9 mm (2.3 in) |
| 2020 | 89.7 mm (3.5 in) |
| 2021 | 48.5 mm (1.9 in) |
| 2022 | 45.0 mm (1.8 in) |
| 2023 | 85.1 mm (3.4 in) |
| 2024 | 41.7 mm (1.6 in) |
| 2025 | 47.2 mm (1.9 in) |
| 2026 | 61.7 mm (2.4 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1958 | 35.6 mm (1.4 in) |
| 1959 | 78.7 mm (3.1 in) |
| 1960 | 71.9 mm (2.8 in) |
| 1961 | 122.2 mm (4.8 in) |
| 1962 | 73.9 mm (2.9 in) |
| 1963 | 58.9 mm (2.3 in) |
| 1964 | 62.9 mm (2.5 in) |
| 1965 | 65.8 mm (2.6 in) |
| 1966 | 81.8 mm (3.2 in) |
| 1967 | 98.3 mm (3.9 in) |
| 1968 | 102.9 mm (4.1 in) |
| 1969 | 139.5 mm (5.5 in) |
| 1970 | 92.9 mm (3.7 in) |
| 1971 | 72.6 mm (2.9 in) |
| 1972 | 112.3 mm (4.4 in) |
| 1973 | 75.8 mm (3.0 in) |
| 1974 | 71.9 mm (2.8 in) |
| 1975 | 105.4 mm (4.1 in) |
| 1976 | 103.5 mm (4.1 in) |
| 1977 | 58.9 mm (2.3 in) |
| 1978 | 157.5 mm (6.2 in) |
| 1979 | 61.0 mm (2.4 in) |
| 1980 | 89.4 mm (3.5 in) |
| 1981 | 88.1 mm (3.5 in) |
| 1982 | 136.4 mm (5.4 in) |
| 1983 | 101.6 mm (4.0 in) |
| 1984 | 65.5 mm (2.6 in) |
| 1985 | 76.2 mm (3.0 in) |
| 1986 | 98.8 mm (3.9 in) |
| 1987 | 326.1 mm (12.8 in) |
| 1988 | 95.0 mm (3.7 in) |
| 1989 | 110.5 mm (4.4 in) |
| 1990 | 137.9 mm (5.4 in) |
| 1991 | 80.4 mm (3.2 in) |
| 1992 | 76.2 mm (3.0 in) |
| 1993 | 88.9 mm (3.5 in) |
| 1994 | 114.5 mm (4.5 in) |
| 1995 | 65.5 mm (2.6 in) |
| 1996 | 82.5 mm (3.2 in) |
| 1997 | 103.7 mm (4.1 in) |
| 1998 | 94.7 mm (3.7 in) |
| 1999 | 86.4 mm (3.4 in) |
| 2000 | 106.9 mm (4.2 in) |
| 2001 | 123.8 mm (4.9 in) |
| 2002 | 121.7 mm (4.8 in) |
| 2003 | 110.3 mm (4.3 in) |
| 2004 | 84.3 mm (3.3 in) |
| 2005 | 41.9 mm (1.6 in) |
| 2006 | 87.6 mm (3.4 in) |
| 2007 | 126.0 mm (5.0 in) |
| 2008 | 214.7 mm (8.5 in) |
| 2009 | 135.0 mm (5.3 in) |
| 2010 | 163.7 mm (6.4 in) |
| 2011 | 219.2 mm (8.6 in) |
| 2012 | 73.3 mm (2.9 in) |
| 2013 | 150.7 mm (5.9 in) |
| 2014 | 85.3 mm (3.4 in) |
| 2015 | 100.6 mm (4.0 in) |
| 2016 | 78.6 mm (3.1 in) |
| 2017 | 146.3 mm (5.8 in) |
| 2018 | 79.4 mm (3.1 in) |
| 2019 | 113.5 mm (4.5 in) |
| 2020 | 202.2 mm (8.0 in) |
| 2021 | 77.5 mm (3.1 in) |
| 2022 | 73.4 mm (2.9 in) |
| 2023 | 108.7 mm (4.3 in) |
| 2024 | 95.8 mm (3.8 in) |
| 2025 | 105.6 mm (4.2 in) |
| 2026 | 95.5 mm (3.8 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1958 | 18 days |
| 1959 | 23 days |
| 1960 | 18 days |
| 1961 | 16 days |
| 1962 | 20 days |
| 1963 | 27 days |
| 1964 | 20 days |
| 1965 | 15 days |
| 1966 | 19 days |
| 1967 | 17 days |
| 1968 | 20 days |
| 1969 | 25 days |
| 1970 | 15 days |
| 1971 | 13 days |
| 1972 | 13 days |
| 1973 | 14 days |
| 1974 | 15 days |
| 1975 | 14 days |
| 1976 | 26 days |
| 1977 | 15 days |
| 1978 | 14 days |
| 1979 | 32 days |
| 1980 | 17 days |
| 1981 | 29 days |
| 1982 | 18 days |
| 1983 | 17 days |
| 1984 | 16 days |
| 1985 | 14 days |
| 1986 | 22 days |
| 1987 | 17 days |
| 1988 | 27 days |
| 1989 | 22 days |
| 1990 | 16 days |
| 1991 | 23 days |
| 1992 | 23 days |
| 1993 | 20 days |
| 1994 | 16 days |
| 1995 | 29 days |
| 1996 | 20 days |
| 1997 | 14 days |
| 1998 | 25 days |
| 1999 | 24 days |
| 2000 | 19 days |
| 2001 | 20 days |
| 2002 | 19 days |
| 2003 | 22 days |
| 2004 | 21 days |
| 2005 | 25 days |
| 2006 | 17 days |
| 2007 | 15 days |
| 2008 | 14 days |
| 2009 | 22 days |
| 2010 | 15 days |
| 2011 | 19 days |
| 2012 | 15 days |
| 2013 | 18 days |
| 2014 | 26 days |
| 2015 | 21 days |
| 2016 | 15 days |
| 2017 | 16 days |
| 2018 | 13 days |
| 2019 | 18 days |
| 2020 | 16 days |
| 2021 | 18 days |
| 2022 | 14 days |
| 2023 | 19 days |
| 2024 | 22 days |
| 2025 | 19 days |
| 2026 | 22 days |
Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.
Frost Dates and Growing Season
67 years with a frostAcross 67 years with a frost, the median last spring frost at Chicago Ohare Intl AP falls on 22 April and the median first autumn frost on 15 October, which leaves a median of 174 days between them.
In 1996 to 2025 the median growing season was 186 days. That is 17 days more than in 1959 to 1988.
Fitted over all years, the growing season changes by +5.8 days per decade at this station.
| Measure | Median, all years | Earliest period (1959 to 1988) | Recent period (1996 to 2025) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 22 April | 28 April | 20 April | 8 days earlier | -2.2 days per decade |
| First autumn frost | 15 October | 13 October | 28 October | 15 days later | +3.6 days per decade |
| Growing days | 174 days | 169 days | 186 days | 17 days more | +5.8 days per decade |
A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.
Rainfall Return Levels
67 years, 1959 to 2025A day with at least 63.4 mm (2.5 in) of rain is expected about once in 2 years. A day with at least 182.8 mm (7.2 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 63.4 mm (2.5 in) | |
| 5 years | 88.2 mm (3.5 in) | |
| 10 years | 107.2 mm (4.2 in) | |
| 25 years | 134.5 mm (5.3 in) | |
| 50 years | 157.4 mm (6.2 in) | |
| 100 years | 182.8 mm (7.2 in) | Longer than the 67 years of record |
The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 67 years of values from 1959 to 2025.
A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.
The largest wettest-day totals in the fit: 174.2 mm (6.9 in) in 2011; 168.7 mm (6.6 in) in 2008; 164.8 mm (6.5 in) in 1987.
Station Changes
2 suspected2 changes were suspected in the annual mean temperature of Chicago Ohare Intl AP, at 1980 and 2017. Each is measured against neighbouring stations.
- Relative to 5 neighbouring stations, the station's annual mean temperature from 1980 ran 0.5 C (0.8 F) lower than in the years before (likely change).
- Relative to 5 neighbouring stations, the station's annual mean temperature from 2017 ran 0.4 C (0.7 F) higher than in the years before (likely change).
| Year | Shift (C) | Shift (F) | Strength | Neighbours |
|---|---|---|---|---|
| 1980 | -0.5 | -0.8 | likely | 5 |
| 2017 | +0.4 | +0.7 | likely | 5 |
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
Climate Twins
2011 to 2025 against 1961 to 1990Over 2011 to 2025, Chicago Ohare Intl AP had a mean temperature of 11.0 C (51.8 F) and 975.8 mm (38.4 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Indianapolis SE Side (United States, 295 km away), Muncie Delaware Co AP (United States, 286 km away) and Dayton Intl AP (United States, 387 km away).
| Twin station | Country | Distance away | Mean temperature, 1961-1990 | Rain a year, 1961-1990 | Climate difference |
|---|---|---|---|---|---|
| Indianapolis SE Side | United States | 295 km (183 mi) | 11.2 C (52.2 F) | 977.3 mm (38.5 in) | 0.64 |
| Muncie Delaware Co AP | United States | 286 km (178 mi) | 10.7 C (51.3 F) | 979.2 mm (38.6 in) | 0.67 |
| Dayton Intl AP | United States | 387 km (240 mi) | 11.0 C (51.7 F) | 931.4 mm (36.7 in) | 0.74 |
Twins are stations, not cities. A twin is one of the three stations at least 100 km away whose earlier climate is closest to this station's recent one, so a close match does not mean the two places look alike in other ways. A station move or a gap in a record can change that station's averages. The list describes past climate; it is not a forecast and does not say what caused any change. How twins are found, and a search for any station.
Download the Data
Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-16 (16 October 2026). Records are computed by this site and are not official.
Data as of . Last revised (2026-10-16).