Will a heat pump pay off in Lewiston, ID?
Here in Lewiston, the honest answer is that a heat pump raises your annual running cost. Swap a failed furnace and AC for a heat pump rather than buying like-for-like, and the extra cost here runs $3,500 after a $2,000 federal tax credit. The heat pump would cost about $95 more a year to run than the furnace it replaces — a premium with no payback. That's Lewiston's own climate and rates talking, not a hedge or a caveat.
Lewiston's weather, in the numbers that matter
Degree days tell the story here: Lewiston racks up 4626 heating degree days each year (base 65°F), and summers are hot enough that cooling matters as much as heating, with 1222 cooling degree days on the cooling side. 1.9°F is the figure equipment gets sized against here — the 99th-percentile cold snap, not an average day — with a record low of -9.9°F on file. Worked through the model, that's a seasonal COP of 2.75 on the cold-climate unit fit for this climate. Below the 25°F line where a standard machine starts leaning on resistance backup, Lewiston sits firmly in cold-climate territory, so that's the class of unit priced here. Source: NOAA station LEWISTON-NEZ PERCE COUNTY AIR, 1.6 miles from Lewiston — the closest one on record.
What it actually costs to run, year to year
A 2000-square-foot house here would pull roughly 4,260 heating kilowatt-hours annually on top of cooling, totalling about $664 a year on electricity. Lewiston's gas rate of 7.69 per Mcf, applied to the 48 Mcf a year the furnace burns, puts its running cost near $569 a year, against 12.52¢ per kWh for electricity. Buy it outright, not incrementally, and payback stretches to beyond the 15-year equipment life; over 15 years the net position sits $4,925 behind.
Electric resistance heat in Lewiston, compared
Plenty of homes in Lewiston heat with electricity alone, no gas line involved. Against electric-resistance heat — baseboard or an electric furnace, both 100% efficient but still just resistance — the case for switching gets stronger here. The saving here runs about $1,001 a year, which recovers the extra $8,000 spent going electric in roughly 8 years.
Where Lewiston ranks in this dataset
Among 3206 cities, Lewiston's winter puts it at rank 1063 for severity, while its size puts it at rank 1183 for population — 1 in both cases being the extreme. That's the coldest third of the dataset, where climate does most of the work behind this figure.
What to do with this number in Lewiston
Lewiston, Idaho is home to about 34,693 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 Lewiston, nothing is lost by holding off until the current equipment genuinely fails.
Get quotes from local HVAC contractors before deciding.
More on how this number was built
Nothing above is a black box: the methodology guide shows the full arithmetic behind Lewiston's 2.75 seasonal COP and payback figure. Lewiston's 1.9°F design temperature falls on the cold side of the 25°F cutoff the cold-climate unit guide walks through.