Washington energy rates pre-filled from EIA. Estimate your heating cost below, and see the assumptions behind every figure.
Electricity: EIA Electric Power Monthly, Table 5.6.A, May 2026. That is a single month, not a 2026 annual average — annual state figures are not published until the following year. Natural gas: EIA Natural Gas Monthly residential price, winter average, Dec 2025 – Feb 2026, converted to $/therm. “Lowest running cost” is a calculation from those rates, not a survey of what people own: it is whichever system delivers a unit of heat for the least money in Washington, comparing a heat pump at a seasonal COP of 2.4 against a 92% AFUE gas furnace. Rates vary by provider and season.
Washington averages 33°F in winter. With cool winters (avg 33.0°F) and delivered-heat costs within 4% of each other, a dual-fuel system that switches between heat pump and gas backup is the most economical setup.
Heat pump and gas furnace running costs sit within 4% of each other in Washington ($0.0183 vs $0.0175 per 1,000 BTU delivered), so a dual-fuel system that switches to gas on the coldest days is the most economical setup here.
Washington electricity costs 14.95¢/kWh, about 19% below the US average of 18.44¢/kWh (EIA Electric Power Monthly, Table 5.6.A, May 2026), which makes electric heating comparatively affordable here.
Compare Washington against other states using our heating cost by state index, or use our free heating cost calculator to estimate your monthly spend.
Based on Washington EIA rates: 14.95¢/kWh electricity (May 2026), $1.61/therm gas (winter average, Dec 2025 – Feb 2026).
| Heater Type | Small Home | Medium Home | Large Home |
|---|---|---|---|
| Electric Resistance | ~$303/mo | ~$505/mo | ~$757/mo |
| Gas Furnace (92% AFUE) | ~$121/mo | ~$202/mo | ~$303/mo |
| Heat Pump (COP 2.4) | ~$126/mo | ~$210/mo | ~$315/mo |
How these are worked out. Whole-home heating for a full winter month, not a plug-in heater. We take Washington's 33°F average winter temperature, which gives about 960 heating degree days in a 30-day month against a 65°F base, and multiply by a heat-loss coefficient of 300 (small, ~1,000 sq ft), 500 (medium, ~2,000 sq ft) or 750 BTU/hr/°F (large, ~3,000 sq ft) for an average-insulated home. That delivered heat is then priced at the rates above, at the efficiencies shown in each row. Those coefficients are round engineering figures, not measurements — they exist so every page on this site derives monthly cost the same way. A poorly sealed house can easily run double these numbers.
Figures above are calculated from EIA Electric Power Monthly, Table 5.6.A (May 2026) and EIA residential natural gas prices, using a seasonal COP of 2.4 for a heat pump in Washington's climate and 92% AFUE for a modern condensing gas furnace.