Cooling · Montana
How Much Does It Cost to Run a Central Air Conditioner in Montana?
The short answer
A typical 3,500W central air conditioner costs about $0.52 per hour to run in Montana, or $128 a month at 8 hours a day.
Montana’s average residential rate was 15.0¢ per kWh in July 2026 (EIA), 18% below the US average.
Source: U.S. EIA, July 2026 data · Updated
Central Air Conditioner cost by daily use in Montana
| Daily use | kWh/month | Per day | Per month | Per year |
|---|---|---|---|---|
| 1 hour/day | 106.5 | $0.52 | $15.96 | $191 |
| 2 hours/day | 212.9 | $1.05 | $31.92 | $383 |
| 4 hours/day | 425.9 | $2.10 | $63.84 | $766 |
| 8 hours/day | 851.8 | $4.20 | $128 | $1,532 |
| 12 hours/day | 1,277.6 | $6.30 | $192 | $2,298 |
| 24 hours/day | 2,555.3 | $12.59 | $383 | $4,596 |
Montana vs other states
At typical use, a central air conditioner costs $1,532 a year in Montana — $3,374 less than in Hawaii and $232 more than in Louisiana.
Montana has the 14th-cheapest residential electricity of the 50 states and DC. Montana price per kWh · all states ranked
Electricity price trend in Montana
15.0¢/kWh in July 2026 — ▲ +5.0% from a year earlier.
How to lower the cost of running a central air conditioner
Central AC is usually the single largest electricity user in a home during summer. Power draw depends on capacity (tons) and efficiency (SEER2 rating): a 3-ton system typically draws 3–4 kW while running. The compressor cycles on and off to hold your thermostat setting, so enter the hours per day it actually runs — on a hot afternoon that can be most of the day, while on a mild day it may be only a few hours.
- Each degree you raise the thermostat in summer saves roughly 3% on cooling.
- Replace the air filter every 1–3 months and keep the outdoor condenser clear of debris.
- Use ceiling fans so you can set the thermostat 3–4°F higher with the same comfort.
- Summers in Montana are relatively mild, so cooling costs are concentrated in a few hot weeks each year.
Questions
Frequently asked questions
How much does it cost to run a central air conditioner for 24 hours in Montana?
Running a 3,500W central air conditioner for 24 hours uses about 84.0 kWh, which costs about $12.59 at Montana’s average rate of 15.0¢/kWh.
How many kWh does a central air conditioner use per month?
At 8 hours a day, a typical central air conditioner uses about 852 kWh a month. In Montana that costs $128.
Is it expensive to run a central air conditioner in Montana?
Montana has the 14th-cheapest residential electricity of the 50 states and DC at 15.0¢/kWh — cheaper than most. Running a central air conditioner here costs about $1,532 a year at typical use, compared with $1,871 at the national average rate.
What is the electricity rate in Montana right now?
The average residential electricity rate in Montana was 15.0¢ per kWh in July 2026, according to the latest EIA data — up 5.0% from a year earlier.
How many watts does a central air conditioner use?
Most residential central AC systems draw 2,000–5,000W while running; a typical 3-ton system uses about 3,500W.
Central Air Conditioner costs in nearby states
Other appliances in Montana
Cheapest and priciest states
Comparisons
Sources & method
- Electricity rates: U.S. Energy Information Administration, Electric Power Monthly — average residential retail price, July 2026 (latest available). Retrieved .
- CO₂: EIA State Electricity Profiles, 2024 emissions rate of in-state power generation.
- Default usage for central air conditioner: 8 hours a day. Typical power 3,500W.
- Formulas, duty cycles and limitations: methodology. Data download: open data (CC BY 4.0).