Summer and winter electricity bills, state by state

In the median state the heaviest month uses 1.8 times as much electricity as the lightest, while the dearest month per kWh costs 13% more than the cheapest. The gap between a summer and a spring bill is mostly how much a home uses, not what each kilowatt-hour costs: in the median state the highest month’s average bill is 1.7 times the lowest month’s.

July is the most expensive month in 28 states and August in 11. April is the cheapest in 29, the lull between heating and cooling.

The widest gaps are in Arizona, where July averages 2.6 times February; New Jersey, where July averages 2.5 times April; Nevada, where July averages 2.4 times November; Oklahoma, where August averages 2.2 times April; and Missouri, where July averages 2.1 times April. At the other end, Hawaii’s highest month, August, is 1.3 times its lowest.

In Alaska, Idaho, Maine, Montana, New Hampshire, North Dakota, Oregon, South Dakota, Vermont, Washington, West Virginia and Wyoming the dearest month falls between December and February. These states have fewer homes with air conditioning, a median of 76% against 93% where bills peak in summer, and the homes that have it run it for about 999 kWh a year against 1,833. That describes the two groups in the federal survey; it is not a measure of what heats or cools any one home.

Many utilities offer budget or levelized billing, which spreads a year’s bills into equal monthly payments and settles the difference later. It changes when a household pays, not how much. The table above shows how uneven the year is where you live; a state’s own page shows what its plans charge.

• Electricity prices this month, state by state
• What each utility's customers paid per kilowatt-hour
• Where households buy electricity from someone other than their utility

Every figure here is computed when the site is built, from the records named below, by the same code that fills the state, utility and cost-to-run pages this guide links to. When those records are refreshed, the figures change with them; the words around them do not, which is why no sentence here states a direction the data has not been checked for.

The text was reviewed by the editor before publication. The methodology page sets out what the rate engine assumes and where its figures stop being reliable.