How much does it cost to run an air conditioner in Colorado?

Short answer

A 3-ton central air conditioner in Colorado costs about $31.74 in July and $76.00 a year at 16.80¢/kWh; an 8,000 BTU window unit about $6.20 in July.

• Colorado pays 16.80¢/kWh on average for Jan–Aug 2026 — 8% below the U.S. average of 18.19¢, the 22nd most expensive of the 50 states and DC.
• Colorado averages 273 cooling degree days a year against 1,216 nationally (NOAA), so we estimate 168 full-load cooling hours — 2.3 a day in July.
• A new 3-ton split system sold for Colorado must reach at least SEER2 13.4 (DOE northern region); it draws about 2.69 kW on average and $0.45 an hour.
• Moving up to the ENERGY STAR average of about SEER2 17 would cut the yearly bill to $59.90 — $16.09 a year less.
• The average Colorado home used 678 kWh a month in 2025; this system adds 189 kWh in July.