Grand Rapids, Michigan, climate update for December 2017
Max Temp: Actual 61, Mean 53, 2017 Max 96, Mean Max 94
Min Temp: Actual -12, Mean 4, 2017 Min -12, Mean Min -7
Av. Temp: Actual 24.4, Mean 28.3, Annual Actual 50.3, Annual Mean 48.2
CDD: 2017 Actual 719, Annual Mean 690
Rain: Actual 1.96, Mean 2.43, Annual Actual 39.43, Annual Mean 34.52
Snow: Actual 32.9, Mean 16.2, Season to Date Actual 33.5, Season to Date Mean 22.9
HDD: Actual 1252, Mean 1131, Season to Date Actual 2443, Season to Date Mean 2488
The warming need as expressed by Heating Degree Days thus far into the cool season increased considerably in December and is now running just 1.8% under the mean to date overall.
The year 2012 remained the warmest full year on record by average temperature at 52.8 F going back to 1898, followed by 1931, 1921, 1998, 2016, 2010, 1938, 1939 and now 2017 at 50.3 F placing ninth. The cooling need in the warm season as expressed by Cooling Degree Days was 4.2% above the annual mean. 2017 actual average temperature exceeded the annual mean average temperature by a similar value, 4.35%. The record year 2012 exceeded annual mean average temperature by 9.5%.
