We may very well have had our last 90-degree day of 2020. The total number of 90-degrees days for the summer of 2020 stands at 22 for Kalamazoo, 17 for Grand Rapids, 16 for Battle Creek, 15 for both Lansing and for the Muskegon Airport, 11 for Holland and 10 for Jackson. Besides the weather, other factors like location and ground cover determine how hot it can get. There is always some variation (Jackson with 10 ninety-degree days and Muskegon – near Lake Michigan and farther north – with 15 ninety-degree days.
The number of 90-degree days varies considerably from year-to-year. Note the 32 ninety-degree days in 2012 in Grand Rapids and then none two years later in 2014. We also did not have a 90-degree day in the summer of 1951 in Grand Rapids. Since 1964, the greatest number of 90-degree days in Grand Rapids has been 37 in the very dry summer of 1988. That summer had 14 days that reached 95° and one day that soared to 100°