Should Rock Island switch to a heat pump?
Here in Rock Island, the honest answer is that a heat pump raises your annual running cost. 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). The heat pump would cost about $304 more a year to run than the furnace it replaces — a premium with no payback. That's Rock Island's own climate and rates talking, not a hedge or a caveat.
How cold Rock Island actually gets
Degree days tell the story here: Rock Island racks up 4885 heating degree days each year (base 65°F), and summers are hot enough that cooling matters as much as heating, with 1062 cooling degree days on the cooling side. The 99% winter design temperature here — the cold snap equipment must be sized for, not the seasonal average — is -11°F, against a record low of -18.9°F. That puts the seasonal coefficient of performance at 2.44 for the recommended cold-climate unit. Below the 25°F line where a standard machine starts leaning on resistance backup, Rock Island sits firmly in cold-climate territory, so that's the class of unit priced here. Source: NOAA station QUAD CITY INTERNATIONAL AIRPO, 3.2 miles from Rock Island — the closest one on record.
Rock Island's running-cost comparison, in dollars
Modelled on a typical 2000-square-foot house, the heat pump draws about 5,069 kWh a year to keep it warm, plus cooling, for a combined electric bill near $1,139 a year. That compares with roughly 51 Mcf a year of gas at Rock Island's 11.25 per-Mcf rate — about $835 a year — against a local electricity rate of 19.06¢/kWh. Priced as a standalone purchase rather than against a like-for-like replacement, equipment payback runs past the 15-year equipment life, for a 15-year net position $8,062 behind.
The other scenario: no gas furnace to begin with
Plenty of homes in Rock Island heat with electricity alone, no gas line involved. Compared with baseboard or electric-furnace resistance heat, the numbers shift in the heat pump’s favor. About $1,481 a year comes back this way, enough that the 5.4-year payback clears the $8,000 premium comfortably within the equipment's life.
How Rock Island compares nationally
Among 3206 cities, Rock Island's winter puts it at rank 875 for severity, while its size puts it at rank 1135 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 Rock Island
Rock Island, Illinois is home to about 36,434 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 Rock Island, nothing is lost by holding off until the current equipment genuinely fails.
Get quotes from local HVAC contractors before deciding.
Where Rock Island's figure comes from
Nothing above is a black box: the methodology guide shows the full arithmetic behind Rock Island's 2.44 seasonal COP and payback figure. Rock Island's -11°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.