The mean temperature at Detroit in January 2012 was 30.7F. This compares to a 1971-2000 normal of 29.7 in Covington, KY; and 32.0 in Lexington, KY.
The mean temperature in Detroit in February 2012 was 32.6F. This compares to a 1971-2000 normal of 34.1 in Covington, KY; and 36.4 in Lexington, KY.
The mean temperature in Detroit in March 2012 was 50.7F. This compares to a 1971-2000 normal of 43.9 in Covington, KY; and 45.6 in Lexington, KY.
The mean temperature in Detroit in April 2012 was 49.4F. This compares to a 1971-2000 normal of 53.7 in Covington, KY; and 54.6 in Lexington, KY.
The mean temperature in Detroit in May 2012 was 65.3F. This compares to a 1971-2000 normal of 63.7 in Covington, KY; and 63.8 in Lexington, KY.
The mean temperature in Detroit for the first 24 days of this month was 71.3F. This compares to a 1971-2000 normal for the first 24 days of June of 71.4 in Covington, KY; and 71.6 in Lexington, KY.
Overall, for the January 1 through June 24 period at Detroit, the mean temperature has been 49.4F. This is 0.7 degrees above the 1971-2000 normal of 48.7 for Covington, KY; and 0.6 degrees below the 1971-2000 normal of 50.0 for Lexington, KY.
What does this mean? Well, this year has been particularly hot due to a combination of factors -- a changing climate and natural variation. However, these extreme temperatures are consistent with climate change theory and will be present more often in the near future. Should nothing be done to limit climate change, the 2012 temperatures in Detroit will likely be the normal by the middle of the century. That is, temperatures in Detroit will likely resemble those of late 20th Century Northern and Central Kentucky. By the end of this Century, the climate in Detroit is likely to resemble places even further south. In fact, by 2100, the temperatures at Detroit could be near late 20th Century Arkansas or Tennessee, or perhaps even northern Alabama!