Temperature averaged 60.4 degrees F, according to the preliminary monthly climate data for May 2016 in Grand Rapids, MI. The cumulative reported total anomaly year to date rises 1.7 from +7.3 last month to +9.0 degrees F in May. Using the full NOW data set going back to 1892, however, the cumulative temperature anomaly for the first five months of 2016 is +15.9 degrees F.
Snowfall was only a trace in May, still totaling 61.1 inches to date, but now 4.9 inches below the long term mean average of 66 inches, with one month left in the measuring period.
Heating degree days (HDD) in May at 206 were 18.25% below the long term normal for the month. The long term mean expected HDD to date would be 6663. Actual HDD to date were 5596, 16% below normal, thanks to the El Nino, with one month left in the measuring period.
It is notable that neither this El Nino nor any other since 1950 has come close to producing the warm winter Grand Rapids experienced in 2011-2012 when the heating degree day measurement hit an all time record low of 5253. Placeholders two and three for warmest winters by HDD after 2011-12 were 1920-21 at 5520 and 1931-32 at 5619. 2015-2016 looks set to join the list, however, of the top five warmest winters by HDD.
