Never in 142 years of official weather observations in Chicago has a July 23-29 period been as cool as the one just completed. Temperatures during that time frame averaged 65.6-degrees—well below the long-term average of 74.5.
The period includes this past weekend which generated an average temperature of 60.8 degrees—cool enough to have tied with three other Chicago weekends since 1871 as the city’s second-coolest ever to occur in a July. Only the weekend of July 3-4, 1909 was cooler and it should be noted it occurred when official temperatures were taken at a site in downtown Chicago, physically closer to Lake Michigan and therefore cooler!
While the intensity of the cool temps is to ease a bit in coming days, the predicted increase in readings will be modest which suggests the recent below normal temperature regime is likely to extend into the opening week of August 2013. The new month gets underway Thursday.
The month moves into its final 2 days with temps running 6-degrees behind a year ago and air conditioning use 56% off last July’s pace
Just two days remain in July 2013, a month with an average temperature which is running nearly 6-degrees behind a year ago.
An estimate of air conditioning based on area temperatures suggests July usage is running 56% lower than the same period a year ago.
Despite recent chill, meteorological summer 2013 averaging close to historic norms
You might think, based on the preponderance of cool temperatures over the past week, that meteorological summer 2013 (which began June 1) is running cooler than normal. But,that’s not the case.
Since the season began, Chicago’s average temperature has registered 71.0-degrees. That’s just 0.2-degree off the city’s official long-term average dating back to 1871 and a reading which ranks 69th warmest of the past 142 summer seasons.
Put a bit differently, 68 meteorological summers to date have been warmer than this one while 75 have been cooler. That makes the season’s temperature a veritable wash.