Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards
US heating demand has fallen 7.2% across 41 seasons of federal records, from an average of 4,339 heating degree days in the first decade of the series to 4,027 in the last. The 2025-26 season came in at 3,973, 8% below normal.
The same season measured 5,972 heating degree days for households heating with oil and 2,970 for households heating with electricity. Heating demand is not one number, and which number applies to a home depends on where it is and what it burns.
NOAA publishes this data every week, in fixed-width text files written for energy traders. It is the cleanest available measure of how much heating the weather actually demanded, and almost nobody outside commodity desks reads it. The summer counterpart is our cooling degree day index, where demand is rising rather than falling.
This index turns it into the answer to the question people ask each spring: was that a cold winter, and compared with what.
Forty-one seasons
The series below runs from the 1985-86 heating season to 2025-26, population-weighted, national, from NOAA’s Climate Prediction Center. A heating season runs 1 July to 30 June, which is NOAA’s convention and the reason a season is labelled across two calendar years.
The 41-season mean is 4,215 heating degree days. The coldest season in the record is 1995-96 at 4,681; the warmest is 2016-17 at 3,626. The gap between those two seasons is 1,055 heating degree days, which is 29% of the warmest season’s total.
The trend is downward and it is not subtle. Decade means fall from 4,339 across the first ten seasons to 4,027 across the last ten, 312 fewer heating degree days or 7.2%. A least-squares line through all 41 seasons slopes at -96 heating degree days per decade.
For an industry that sizes equipment to design conditions and sells on seasonal load, a 7.2% fall in measured heating demand over four decades is the background against which every electrification and equipment-mix argument takes place.
The same winter, by fuel
This is the part of the NOAA release that goes unused. CPC publishes the national accumulation weighted not just by population but by the population using each heating fuel, which produces a materially different number for each.
| Weighting | Season total (HDD) | Deviation from normal | Percent |
|---|---|---|---|
| Fuel Oil, Kerosene, etc. Heating | 5,972 | -10 | +0% |
| Coal And Coke Heating | 5,631 | -88 | -2% |
| Other Fuel Heating | 5,148 | -350 | -6% |
| Wood Burning Heating | 4,755 | -377 | -7% |
| Utility Gas Customer Heating | 4,442 | -395 | -8% |
| Bottled Tank Lp Gas Heating | 4,420 | -387 | -8% |
| Population | 3,973 | -359 | -8% |
| Solar Energy Heating | 3,755 | -518 | -12% |
| Electricity Heating | 2,970 | -348 | -10% |
| No Fuel Used Population | 2,687 | -467 | -15% |
Households heating with fuel oil faced 5,972 heating degree days last season. Households heating with electricity faced 2,970, 50% fewer. That is not a difference in equipment or efficiency. It is geography: oil heats the Northeast, and resistance and heat pump heating concentrate in the South.
It also explains why national comparisons of heating cost by fuel mislead. A national average cost per household for oil heat and for electric heat are not describing the same winter.
By state
| State | Season total (HDD) | Deviation from normal | Percent |
|---|---|---|---|
| North Dakota | 8,380 | -723 | -8% |
| Minnesota | 8,090 | -381 | -4% |
| Vermont | 8,026 | +366 | +5% |
| Maine | 7,830 | -220 | -3% |
| New Hampshire | 7,460 | -150 | -2% |
| Montana | 7,192 | -661 | -8% |
| Wisconsin | 7,109 | -395 | -5% |
| Wyoming | 6,830 | -1,081 | -14% |
| Michigan | 6,711 | -81 | -1% |
| South Dakota | 6,554 | -912 | -12% |
| Massachusetts | 6,356 | -13 | +0% |
| New York | 6,275 | +128 | +2% |
| State | Season total (HDD) | Deviation from normal | Percent |
|---|---|---|---|
| Arkansas | 2,780 | -605 | -18% |
| Oklahoma | 2,779 | -814 | -23% |
| Nevada | 2,683 | -1,007 | -27% |
| South Carolina | 2,536 | -209 | -8% |
| Georgia | 2,445 | -408 | -14% |
| Alabama | 2,361 | -407 | -15% |
| Mississippi | 1,975 | -514 | -21% |
| California | 1,851 | -732 | -28% |
| Louisiana | 1,552 | -212 | -12% |
| Arizona | 1,470 | -485 | -25% |
| Texas | 1,305 | -606 | -32% |
| Florida | 638 | +15 | +2% |
North Dakota recorded 8,380 heating degree days and Florida recorded 638. A heating system in the first state is asked to do roughly 13 times the work of one in the second across a season, which is the whole reason federal efficiency standards for furnaces and heat pumps are set regionally rather than nationally.
Almost every state came in below normal. The largest shortfalls against normal were in the warm states, where a small absolute deficit is a large percentage: Texas -32%, California -28% and Nevada -27%.
Frequently asked questions
What is a heating degree day?
A heating degree day measures how far the daily mean temperature falls below 65°F. A day averaging 45°F contributes 20 heating degree days. Totalling them across a season gives a single number for how much heating the weather demanded, which is why utilities and energy forecasters use it rather than average temperature.
How cold was the 2025-26 heating season?
Warmer than normal. The US population-weighted total was 3,973 heating degree days, 359 below the NOAA normal, or 8% below. It was also below the 41-season average of 4,215.
Is US heating demand falling?
Yes, on the measured record. The mean of the first ten seasons in this series, 1985-86 onward, was 4,339 heating degree days. The mean of the last ten is 4,027, a fall of 312 or 7.2%. A least-squares trend across all 41 seasons runs at -96 heating degree days per decade.
Which was the coldest and warmest season on record here?
The coldest in this 41-season series was 1995-96 at 4,681 heating degree days. The warmest was 2016-17 at 3,626.
Why does the degree day total differ by heating fuel?
Because fuels are not distributed evenly across the country. NOAA publishes degree days weighted by the population using each fuel. In 2025-26, the fuel-oil-weighted total was 5,972 heating degree days against 2,970 for electricity, because oil heats homes in the cold Northeast while electric heating concentrates in the warm South. The population-weighted figure, 3,973, sits between them.
Which state had the coldest season?
North Dakota at 8,380 heating degree days. Florida had the fewest at 638, a difference of more than 13 times.
Was anywhere colder than normal last season?
Only 9 states, and only marginally. Vermont was +366 heating degree days against normal, Delaware was +198 heating degree days against normal, Rhode Island was +146 heating degree days against normal. Every other state was at or below its normal.
What does this mean for my heating bill?
Degree days measure the demand the weather placed on your system, not the price you paid for the energy to meet it. A season can be warmer than normal and still cost more if fuel prices rose. The two have to be read together, which is why this index sits alongside our heating fuel price coverage rather than replacing it.
What baseline are the normals?
NOAA’s Climate Prediction Center publishes the normals used in these files. CPC marks a deviation as incalculable with the code -999 where a normal is below 100 heating degree days, which happens in the warmest states, and those cells are shown as not available here rather than as zero.
How often is this index updated?
Weekly during the heating season. NOAA publishes state, regional and national accumulations every week, running from 1 July to 30 June. This page carries the completed-season record and is updated as the current season accumulates.
Methodology and limitations
- Source: NOAA Climate Prediction Center, population-weighted degree day summaries for CONUS states, regions and the nation. One file per season is used, the June monthly summary, because CPC accumulates from 1 July and the June file therefore carries the complete season total.
- Coverage: 41 completed heating seasons, 1985-86 to 2025-26. A heating season runs 1 July to 30 June on CPC’s convention.
- A heating degree day is the shortfall of the daily mean temperature below 65°F, summed over the period. Population weighting means each state contributes in proportion to the population it holds, so the national figure describes the heating demand facing the average American rather than the average acre.
- Fuel weightings are CPC’s own. Each weights the same temperature data by the population using that fuel for heating, so differences between them reflect where fuels are used and not how equipment performs.
- Normals are CPC’s published normals for these files. CPC writes -999 where a normal is below 100 heating degree days or a ratio cannot be calculated, which occurs in the warmest states; those cells are reported as not available rather than converted to zero.
- State files cover the contiguous United States. Alaska and Hawaii appear in CPC’s weekly state product but not in this CONUS seasonal series, so they are absent from the state tables.
- Degree days measure weather-driven demand, not energy consumption, not cost, and not what any individual system used. A home’s actual load depends on its envelope, its equipment and its thermostat settings.
- The least-squares trend is descriptive of these 41 observations. It is not a forecast and it is not attributed to any cause here.
- Refresh: weekly during the heating season, from CPC’s weekly state product, and at season close from the June file.
Sources
- NOAA Climate Prediction Center, population-weighted heating degree days, CONUS states, monthly and seasonal files.
- NOAA Climate Prediction Center, weekly and monthly degree day summaries, including the weekly state product and forecast.
- NOAA Climate Prediction Center, Weekly and Monthly Degree Day Summaries Explanation.
The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.
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