Through most of July the city’s normal high temperature holds constant around 84 and there is a similar period around freezing in January. How do they compare? Is there a spring-fall counterpart?
Bill DeMarco, Chicago
Based on the city’s current 1981-2010, 30-year normals, Chicago’s highest-average maximum peaks at 85 for a seven-day period from July 9-15. This peak is sandwiched between an extended period of 84-degree average highs from June 30-July 8 and July 16-29 with the city’s highs peaking at 84 or 85 for 30 days. In the dead of winter, the city experiences its lowest average high of 31 for 28 days from January 2-29 and the cold period expands to a 43-day period from December 25-February 5 when counting highs of both 31 and 32. There is no counterpart in the spring and fall.