A heating degree day (HDD) is a measure of how cold a location is. It’s derived by comparing the average outdoor temperature to a baseline of 65 degrees. More extreme cold temperatures result in a higher number of HDDs, which typically translate to an increased demand for space heating by energy consumers.
The below chart states the number of HDDs that have occurred in the month of December during the past 3 years, as well as the month’s 10-year average (2020-2011), broken down by Census Division.
| Census Division | Dec 2020 | Dec 2019 | Dec 2018 | Dec 10-Year Average |
| New England | 986 | 1061 | 1026 | 994.4 |
| Middle Atlantic | 945 | 972 | 929 | 913.2 |
| East North Central | 1035 | 975 | 1003 | 1027.4 |
| West North Central | 1096 | 1098 | 1103 | 1142 |
| South Atlantic | 555 | 449 | 488 | 432.3 |
| East South Central | 727 | 573 | 634 | 625.1 |
| West South Central | 480 | 418 | 472 | 459.8 |
| Mountain | 879 | 870 | 897 | 899.2 |
| Pacific | 541 | 576 | 564 | 579.9 |
| United States | 749 | 715 | 732 | 731.5 |
Additional HDD data can be found under the Supply and Logistics section on the Member Dashboard of NPGA’s website. For more information, please contact NPGA’s Jacob Peterson.
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