U.S. residential electricity EIA data: July 2026 US average 18.3¢/kWh Updated

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

Cost at 15.0¢/kWh, the Montana average (EIA, Jul 2026)
Daily usekWh/monthPer dayPer monthPer 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.

Sources & method