There has never been a heat wave of this duration and magnitude this late in the season in Chicago. Chicago has never recorded 5 consecutive days with high temperatures greater than 92 degrees this late in the year. The previous latest streak of more than four days in a row of plus 92 degrees was Sept 16-19, 1955.
In addition, this is the latest Chicago has ever recorded 3 days in a row of mid 90s. The previous record for latest three day streak of mid 90s was back on Sept 13-15, 1927 and also the same dates in 1939.
Saturday`s high temperature of 95 degrees is 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 14th back in 1893, 1915, and also 1927.
The daily average temperature on Sept 21 was 83 degrees, which ties for the warmest daily temperature on record after the
midpoint of Sept (Sept 21, 1931).
The last 5 days were record breakers. Last Wednesday 91-degrees set in 1931, Thursday 92-degrees set in 1970, Friday 92-degrees set in 1956, Saturday 91-degrees set in 1931, Sunday 91-degrees set in 1891 and today we should see temp over 90-degrees which would be set another record, set in 1930.