Chicago’s hot summer of 1988

Dear Tom,
With an almost endless string of brutally hot and humid days, the summer of 1988 was the worst I can recall. Has Chicago ever had a comparable three-month period?
— Tom Gregg, Niles

Dear Tom,
The summer of 1988 leads the pack in terms of quantity of heat with the most number of 90-degree-plus days (47) and the most days of triple-digit heat (seven). However, in terms of overall temperature, its average temperature of 75.1 degrees ranks only as the city’s 11th-warmest summer.
Although the 1988 summer was brutally hot, it was a drought summer and not overly humid. Temperatures in the 90s and 100s, when combined with 70-degree-plus dew points, create stifling heat, but that summer dew points were often in the more comfortable 50s and 60s. There were four days that summer that actually registered highs in the 90s and lows in the 50s.
The summer of 1988 leads the pack in terms of quantity of heat with the most number of 90-degree-plus days and the most days of triple-digit heat.