The numbers are in for 2019. Monthly HDDs are shown below for each month of 2019, with totals for the 20-year average and for 2018 also shown. 2019 was warmer than normal by 162 degree days, but was actually slightly cooler than the year before, by just 14 HDDs. The start of this season, October â€“ December, was right on par with the 20-year average, with a colder November offset by a warmer October and December. We’ll see how January 2020 turns out with the recent warm spell, but as they say the jury’s still out. Numbers are for Connecticut generically, and not for any specific city or region. The source is NOAA, the National Oceanic and Atmospheric Administration.