Skip to main content
HeatPrice

Heating degree day (HDD)

An oddly-named metric for predicting how much fuel is used.

Glossary termNo. 9 / 10
Category
Tank & usage
Fuel
Source
EIA / NWS

A measure of how cold a day is for heating purposes: how far the day's average temperature falls below 65°F. A day that averages 25°F counts as 40 heating degree days (65 − 25).


Dealers and analysts add up HDD to gauge fuel demand — a stretch of cold piles up degree days, which both raises how fast you burn oil and can strain local delivery when everyone needs a fill at once.

Cross-references
K-factor
The "miles per gallon" of your heat.
Automatic delivery
Skip the hassle. The dealer schedules the fill.