How much does it cost to run an air conditioner in District of Columbia?

Short answer

A 3-ton central air conditioner in District of Columbia costs about $176.02 in July and $591 a year at 24.86¢/kWh; an 8,000 BTU window unit about $36.73 in July.

• District of Columbia pays 24.86¢/kWh on average for Jan–Aug 2026 — 37% above the U.S. average of 18.19¢, the 10th most expensive of the 50 states and DC.
• District of Columbia averages 1,531 cooling degree days a year against 1,216 nationally (NOAA), so we estimate 944 full-load cooling hours — 9.1 a day in July.
• A new 3-ton split system sold for District of Columbia must reach at least SEER2 14.3 (DOE southeast region); it draws about 2.52 kW on average and $0.63 an hour.
• Moving up to the ENERGY STAR average of about SEER2 17 would cut the yearly bill to $497 — $93.86 a year less.
• The average District of Columbia home used 639 kWh a month in 2025; this system adds 708 kWh in July.