Cheapest way to heat in Montana
Natural gas
$9.37 per million Btu of heat in the house, about $801 for a typical winter. The most expensive option, heating oil, would cost $4,526.
Typical winter: a 2,000 sq ft house of average insulation in a normal Montana heating season. Prices as of October 26, 2026.
Cost of one million Btu of heat
Your home, your winter
Change the size and insulation to match your house. Prices are this week’s Montana figures.
Normal heating season in Montana: 8,548 heating degree days, so about 85 million Btu of heat to deliver.
- Natural gas $801
- Heat pump $1,416
- Propane $2,396
- Electric resistance $3,540
- Heating oil $4,526
A typical-weather season at this week’s fuel prices. Efficiencies: gas furnace 90%, propane and oil 85%, heat pump seasonal COP 2.5. How the estimate works
Montana’s winters
A normal heating season here has 8,548 heating degree days (1991–2020 average; U.S. lower 48: about 4,300).
Last season (2025–26) had 7,399, −13.4% against normal.
- Oct712
- Nov1,033
- Dec1,305
- Jan1,306
- Feb1,127
- Mar1,003
- Apr749
In the coldest season of the last 30 (1996–97) the same house would have needed 8% more heat; in the mildest (2025–26), 13% less.
What this comparison leaves out
- Equipment you already have. Switching fuels means new equipment. This page compares the cost of heat, not the cost of a new furnace, boiler or heat pump.
- Availability. Natural gas needs a utility main on your street. EIA does not survey heating oil prices in Montana, so the regional or U.S. average stands in; local prices can differ.
- Heat pumps in deep cold. A heat pump’s efficiency falls as it gets colder. The seasonal COP of 2.5 used here suits a modern unit in a moderate climate; older units, or cold-climate homes with resistance backup, do worse.
- Your rate structure. Gas and electricity prices here are state averages including fixed charges. Each extra unit on your bill may cost a little less.
