AC running cost in Montana
A typical 2,000 sq ft Montana home with average insulation and a 14 SEER2 central AC uses about 223 kWh a year for cooling: roughly $31, peaking in Jul at about $14.
At a glance
Montana ranks 47th of 48 contiguous states for estimated yearly AC running cost. Its residential electricity price (13.95¢/kWh) is 23% lower than the U.S. average (18.19¢, EIA) and ranks 38th highest. Its climate brings 197 cooling degree days a year (47th most), so cooling demand is 82% lower than the 48-state average. Jul is the peak month, carrying about 47% of the year's AC cost; the meaningful cooling season runs Jun–Sep.
| Estimated yearly AC cost (2,000 sq ft, 14 SEER2) | $31 |
| Average across 48 contiguous states (unweighted) | $207 |
| Average residential price, July 2026 YTD | 13.95¢/kWh (U.S.: 18.19¢) |
| Single month, July 2026 | 14.99¢/kWh |
| Annual cooling degree days (NOAA, 1991–2020, base 65°F) | 197 (48-state avg 1,099) |
| Yearly savings, 18 vs 14 SEER2 | $7 |
We haven't verified utility-specific tariffs for Montana yet, so this page uses the EIA statewide average. Your utility's rate may differ, so enter it in the calculator below.
Sources: EIA Electric Power Monthly, Table 5.6.B and Table 5.6.A; NOAA NCEI nClimDiv. Statewide averages hide large local differences.
Compared with neighboring states
| State | Price | CDD/yr | Yearly AC cost |
|---|---|---|---|
| South Dakota | 14.5¢ | 688 | $113 |
| Idaho | 12.96¢ | 489 | $72 |
| North Dakota | 12.36¢ | 444 | $62 |
| Wyoming | 13.95¢ | 278 | $44 |
| Montana | 13.95¢ | 197 | $31 |
Same home (2,000 sq ft, average insulation, 14 SEER2) in each state.
Month by month
| Month | CDD | kWh | Cost |
|---|---|---|---|
| Jan | 0 | 0 | $0 |
| Feb | 0 | 0 | $0 |
| Mar | 0 | 0 | $0 |
| Apr | 0 | 0 | $0 |
| May | 1 | 2 | $0 |
| Jun | 19 | 22 | $3 |
| Jul ★ | 92 | 104 | $14 |
| Aug | 69 | 78 | $11 |
| Sep | 14 | 16 | $2 |
| Oct | 0 | 0 | $0 |
| Nov | 0 | 0 | $0 |
| Dec | 0 | 0 | $0 |
★ peak month.
Thinking about a new system? See AC replacement cost & savings by state and heat pump vs gas furnace in Montana.
Yearly cooling cost by home size and SEER2
| Home | 13 SEER2 | 14 SEER2 | 16 SEER2 | 18 SEER2 |
|---|---|---|---|---|
| 1,200 sq ft | $20 | $19 | $16 | $15 |
| 1,600 sq ft | $27 | $25 | $22 | $19 |
| 2,000 sq ft | $33 | $31 | $27 | $24 |
| 2,500 sq ft | $42 | $39 | $34 | $30 |
| 3,000 sq ft | $50 | $47 | $41 | $36 |
Average insulation; 13.95¢/kWh.
AC monthly running cost calculator
| Month | Cooling degree days | kWh | Cost |
|---|
Price defaults to the state's EIA average residential price (July 2026 YTD); edit it to match your bill. Climate: NOAA state cooling degree days, 1991–2020 average. How this works.