AC running cost in Illinois
A typical 2,000 sq ft Illinois home with average insulation and a 14 SEER2 central AC uses about 1,006 kWh a year for cooling: roughly $193, peaking in Jul at about $62.
At a glance
Illinois ranks 23rd of 48 contiguous states for estimated yearly AC running cost. Its residential electricity price (19.22¢/kWh) is 6% higher than the U.S. average (18.19¢, EIA) and ranks 13th highest. Its climate brings 889 cooling degree days a year (24th most), so cooling demand is 19% lower than the 48-state average. Jul is the peak month, carrying about 32% of the year's AC cost; the meaningful cooling season runs May–Sep.
| Estimated yearly AC cost (2,000 sq ft, 14 SEER2) | $193 |
| Average across 48 contiguous states (unweighted) | $207 |
| Average residential price, July 2026 YTD | 19.22¢/kWh (U.S.: 18.19¢) |
| Single month, July 2026 | 19.22¢/kWh |
| Annual cooling degree days (NOAA, 1991–2020, base 65°F) | 889 (48-state avg 1,099) |
| Yearly savings, 18 vs 14 SEER2 | $43 |
We haven't verified utility-specific tariffs for Illinois 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 |
|---|---|---|---|
| Missouri | 13.96¢ | 1,265 | $200 |
| Kentucky | 14.27¢ | 1,228 | $198 |
| Illinois | 19.22¢ | 889 | $193 |
| Indiana | 17.04¢ | 911 | $176 |
| Iowa | 14.2¢ | 809 | $130 |
| Wisconsin | 19¢ | 514 | $111 |
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 | 2 | 2 | $0 |
| Apr | 2 | 3 | $1 |
| May | 70 | 80 | $15 |
| Jun | 189 | 214 | $41 |
| Jul ★ | 287 | 325 | $62 |
| Aug | 241 | 273 | $52 |
| Sep | 88 | 100 | $19 |
| Oct | 8 | 9 | $2 |
| 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 Illinois.
Yearly cooling cost by home size and SEER2
| Home | 13 SEER2 | 14 SEER2 | 16 SEER2 | 18 SEER2 |
|---|---|---|---|---|
| 1,200 sq ft | $125 | $116 | $102 | $90 |
| 1,600 sq ft | $167 | $155 | $135 | $120 |
| 2,000 sq ft | $208 | $193 | $169 | $150 |
| 2,500 sq ft | $260 | $242 | $211 | $188 |
| 3,000 sq ft | $312 | $290 | $254 | $226 |
Average insulation; 19.22¢/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.