Washington, MO: the heat pump payback math
Washington technically pencils out, but only past the point the equipment would need replacing anyway. Against a like-for-like gas furnace and AC swap, going electric costs $3,500 more up front here (already netting out a $2,000 tax credit). Washington's residents would see roughly $221 a year back in running costs, putting the payback around 15.8 years. That's a technicality, not a recommendation, for anyone actually living in Washington.
Washington's weather, in the numbers that matter
3754 heating degree days pile up here every year, so Washington has a real but manageable winter; the cooling side runs to 1476 cooling degree days, where summers are hot enough that cooling matters as much as heating. Sizing runs off the design temperature, not the average day: 1.4°F here (record low -7.6°F), which works out to a seasonal COP of 2.73 for the cold-climate class of unit this climate calls for. A cold-climate unit is the right call in Washington — below 25°F design temperature, a standard heat pump leans hard on electric-resistance backup, which erases most of the savings. Climate figures trace to the nearest NOAA station, WASHINGTON REGIONAL AIRPORT, 2.3 miles from Washington.
The month-to-month numbers for Washington
A 2000-square-foot house here would pull roughly 3,482 heating kilowatt-hours annually on top of cooling, totalling about $608 a year on electricity. That compares with roughly 39 Mcf a year of gas at Washington's 14.94 per-Mcf rate — about $830 a year — against a local electricity rate of 12.83¢/kWh. Buy it outright, not incrementally, and payback stretches to 61 years; over 15 years the net position sits $180 behind.
The other scenario: no gas furnace to begin with
Gas isn't universal in Washington — many houses run on electric heat already. Against electric-resistance heat — baseboard or an electric furnace, both 100% efficient but still just resistance — the case for switching gets stronger here. About $857 a year comes back this way, enough that the 9.3-year payback clears the $8,000 premium comfortably within the equipment's life.
How Washington compares nationally
Washington lands at position 1645 out of 3206 cities on heating severity (coldest is 1), and 2345 out of 3206 by population size (biggest is 1). That's the middle third for winter severity among the cities covered here.
What to do with this number in Washington
Washington, Missouri is home to about 15,521 people, and the figures above are the same ones a local HVAC contractor uses to size and quote a system — this site doesn't guess where a real quote would land, it just tells you whether it's worth asking for one. In Washington, nothing is lost by holding off until the current equipment genuinely fails.
Ask a local HVAC contractor for a quote before committing either way.
Where Washington's figure comes from
Every constant behind this page — the 2.73 seasonal COP, the degree-day corrections, the equipment costs — is documented in the methodology guide. Washington's 1.4°F design temperature is below the 25°F line, which is why a cold-climate unit is the right call here — see what that changes in the cold-climate unit guide.