Public Information Statement...UPDATED National Weather Service Chicago IL 912 PM CDT Tue Sep 26 2017 /1012 PM EDT Tue Sep 26 2017/ ...Record Late Season Heat Numbers... Late September 2017 has seen near to record warmth across a sizable portion of the Midwest, including northern Illinois and northwest Indiana. Following are climatological numbers to put this late season heat into perspective. ************************************************************** CHICAGO Records date back to 1871. Date 2017 High Record High 2017 Low Record Warm Minimum -------------------------------------------------------------- 9/20 92* 91 (1931) 62 73 (1931) 9/21 94* 92 (1970) 72 76 (1931) 9/22 94* 92 (1956) 71 73 (1895) 9/23 95* 91 (1937) 72* 71 (1891) 9/24 93* 91 (1891) 70 71 (1930) 9/25 92* 90 (1933) 67 72 (1920) 9/26 92* 90 (1998) 70 71 (1973) * = Record 2017 has seen the latest 90+ since 1998 (Sept 26). Latest 90+ degree reading on record: Oct 6, 1963 (94) Latest 95+ degree reading on record: Sept 29, 1953 (99) There has not been a heat wave of this duration and magnitude this late in the season in Chicago on record. Chicago has not recorded 7 consecutive days with highs of 92F+ this late in the year. The previous latest streak of 4+ days in a row of 92F+ was Sept 16-19, 1955. In fact, this year`s streak of 7 days in a row with highs of 92F+ is only the 2nd time in the past 50 years that Chicago has seen such a stretch of heat. The other time was during the heart of summer in the infamously hot and dry summer of 1988 (July 27-August 4). Until 2017, there had not been 7 consecutive 90+ days in Chicago entirely during the month of September. The previous latest streaks of 7+ days of consecutive 90s were on August 24-September 3, 1953 and August 25-September 3, 1973. In addition, this is the latest Chicago has ever recorded 3 days in a row of mid 90s (94F+). The previous record for latest 3+ day streak of mid 90s was back on Sept 13-15, 1927 and also the same dates in 1939. Saturday`s high temperature of 95F tied for the hottest day of 2017. This sets a record for the latest in the year that the hottest temperature of the year was recorded in Chicago. Previously, the latest in the year that the annual high temperature occurred was Sept 14 in 1893, 1915, and 1927. The daily average temperature on Sept 21 was 83 degrees, which ties for the warmest daily average temperature on record after the midpoint of Sept (Sept 21, 1931). ************************************************************** ROCKFORD Records date back to 1905. Date 2017 High Record High 2017 Low Record Warm Minimum -------------------------------------------------------------- 9/20 91 92 (1920) 63 74 (1895) 9/21 89 94 (1920) 69 70 (1895) 9/22 92 93 (1937) 67* 65 (1959) 9/23 93* 92 (1937) 66^ 66 (1920) 9/24 90 92 (1920) 65 70 (1930) 9/25 92 95 (1920) 64 69 (1972) 9/26 90 92 (1920) 63 69 (1973) * = Record ^ = Record Tied 2017 has seen the latest 90+ since 2010 (Oct 9). Latest 90+ degree reading on record: Oct 9, 2010 (90) Latest 95+ degree reading on record: Sept 25, 1920 (95) Latest stretches of 5+ consecutive days of 90+: 1. September 22-26, 2017 2. September 12-16, 1939 3. September 11-15, 1927 Latest stretches of 4+ consecutive days of 90+: 1. Oct 2-5, 1922 2. Sept 22-26, 2017 3. Sept 12-16, 1939 The latest in the year that the annual high temperature occurred: Sept 15, 1927 (99) The highest temperature in 2017 has been 94 on June 11 and 12. For more, please see weather.gov/chicago and click on Climate and Past Weather. $$ MTF/Izzi/Castro/Rodriguez