How much heating oil do I use per month?
A monthly average hides the picture: by the degree-day normals, about four fifths of a Boston year's heating falls in November through March. If you know your yearly gallons, enter them below. The page spreads the total over the months in proportion to how cold each month normally is in four Northeast cities, and shows when a tank would reach your reserve.
Gallons per month, Boston
Each month gets its share of the 600 gallons. The share is the month's normal heating degree days divided by the year's 5,546. These are my estimates, not measured use.
| Month | Degree days | Share | Gallons |
|---|---|---|---|
| Jan | 1,086 | 19.6% | 117.5 |
| Feb | 930 | 16.8% | 100.6 |
| Mar | 828 | 14.9% | 89.6 |
| Apr | 496 | 8.9% | 53.7 |
| May | 234 | 4.2% | 25.3 |
| Jun | 50 | 0.9% | 5.4 |
| Jul | 4 | 0.1% | 0.4 |
| Aug | 5 | 0.1% | 0.5 |
| Sep | 71 | 1.3% | 7.7 |
| Oct | 326 | 5.9% | 35.2 |
| Nov | 608 | 11.0% | 65.8 |
| Dec | 908 | 16.4% | 98.3 |
How the split works
A heating degree day is how far a day's average outdoor temperature falls below 65 °F, and EIA describes it as a measure of how much heating a building needs (EIA, degree days). A house burns about the same oil per degree day, so a month with a fifth of the year's degree days burns about a fifth of the year's oil. For Boston that gives 118 gallons in January out of 600. The day-by-day version of the same idea is on the heating oil use per day page.
To find the date, the page divides each month's gallons by its days and takes that much out of the tank every day, starting on the 1st of the month you pick. It stops when the level reaches your reserve. A real month runs warmer or colder than normal, so treat the date as a few weeks of warning, and check the stick before relying on it.
What a yearly total looks like
EIA's winter outlook for 2021-22 expected a household that heats with oil to burn 511 gallons over the winter (EIA, Today in Energy). That is an average over all oil-heated homes, so a large old house in Maine can sit far above it and a small tight one far below. The most reliable number is yours: add up the gallons on last year's delivery slips, or take two dated readings and use the run-out page. If the slips cover a different stretch than a calendar year, the total is still a fair stand-in as long as it spans a full heating season.
Four cities side by side
Normal heating degree days per month, 1991-2020. A colder city has more of them, so the same house would burn more there. Portland, Maine has about 23% more than Boston.
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Boston | 1,086 | 930 | 828 | 496 | 234 | 50 | 4 | 5 | 71 | 326 | 608 | 908 | 5,546 |
| Hartford | 1,176 | 991 | 845 | 473 | 193 | 35 | 2 | 6 | 93 | 382 | 683 | 1,004 | 5,883 |
| Albany | 1,260 | 1,070 | 909 | 514 | 204 | 37 | 3 | 10 | 115 | 428 | 737 | 1,071 | 6,357 |
| Portland, ME | 1,271 | 1,088 | 956 | 613 | 325 | 89 | 10 | 16 | 145 | 459 | 749 | 1,074 | 6,795 |
Source: NOAA NCEI 1991-2020 U.S. Climate Normals, monthly heating degree days base 65 °F, from the NCEI data service. Stations: BOSTON LOGAN INTL AP, MA (USW00014739); HARTFORD BRADLEY INTL AP, CT (USW00014740); ALBANY AP, NY (USW00014735); PORTLAND INTL JETPORT, ME (USW00014764). Change stations= in that link to open another city.
What the split leaves out
- Oil hot water burns all year. The split puts all oil into heating, so summer months show near zero while a house with oil hot water still burns some.
- Your street can differ from the airport station. Coastal and hilltop houses differ from the airport by several percent.
- One cold January moves a year's total more than the normals suggest.
Next step
Open the calculator with a 275 gallon tank and a 10% reserve already set, enter two dated dips, and compare the burn rate with this page's estimate.
Related
- Heating oil use per day: gallons by outdoor temperature.
- How long will heating oil last? Days left from your own readings.
- 275 gallon oil tank chart: inches on the stick to gallons.
- Cost to fill an oil tank: what a delivery costs at your price.