Does electricity cost more in summer? At about half of utilities, yes

Summer bills are higher mostly because air conditioning means using more power. But at many utilities the price of each kilowatt-hour rises too, so the same usage costs more in July than it did in January. Whether yours does is written into its tariff.

The same usage, a different price

We priced the same 1,000 kWh of use in every month of the year on every current residential tariff, at 174 utilities:

• 82 have at least one tariff that costs more in July than in January.
• 19 have one that costs more in January.
• 68 charge the same in every month on every tariff they file.

A utility can appear in both of the first two groups, because some file tariffs that move in each direction.

How much more summer costs

At the typical utility that charges more in summer, a July bill for 1,000 kWh is 8.5% higher than a January bill for the same usage, about $12 a month more.

• At 18 utilities the July bill is 20% or more higher.
• At 6 it is 40% or more higher.
• The largest gaps are on time-of-use tariffs with expensive summer peaks. Consolidated Edison's voluntary time-of-day rates in New York City and Westchester bill roughly twice as much in July as in January for the same usage.

That premium comes on top of whatever extra power you use for cooling, which is why a summer bill can jump far more than the thermostat seems to explain.

When summer starts

Utilities do not agree on what summer is, but most come close:

Higher-priced months	Utilities
June to September	43
May to October	7
June to October	6
May to September	6
July to September	5

If a billing period straddles the change, many utilities split it, billing the days before at one price and the days after at the other.

Some utilities charge more in winter

At 19 utilities, at least one tariff costs more in January than in July. The clearest case is Puget Sound Energy in Washington, where demand peaks in winter: its time-of-use pilot tariffs bill 21% to 31% more in January for the same usage.

Elsewhere the effect comes from the tier ladder rather than the price. Several of California's standard tariffs give each household a cheap first block of kWh, the baseline allowance, that is larger in summer than in winter in hot regions. The same 1,000 kWh then costs more in January simply because less of it falls in the cheap block.

What it means for you

• Budget for the premium, not just the usage. If your utility charges more in summer, the same habits cost more from June. Budget billing evens out the payments but not the cost.
• On a seasonal tariff, timing within the day does not help. If the price changes only by month, there is nothing to shift; the lever is how much you use. Time-of-use tariffs are different, and peak hours depend on your utility.
• Compare tariffs over a whole year. A tariff that looks cheap on a winter bill can cost more across twelve months, and the reverse.

How we measured this

• Current tariffs: filed since 2020, priceable from usage alone, priced as a whole home's bill, open to any household and not flagged as a likely data error, the same set this site ranks.
• Same usage every month: 1,000 kWh, spread evenly across every hour, so that the comparison shows the change in price and nothing else. Real households use more in some months and at some hours; this deliberately ignores that.
• Whole bill: fixed charges, tiers and the adjustments each filing lists are included. Charges that change outside the filing, such as fuel or supply adjustments reset during the year, are not.
• Seasonal: a tariff whose dearest month costs more than 1% above its cheapest.
• Counted by utility: many utilities file several tariffs, and counting tariffs lets a few of them decide the result. The typical premium is the median across utilities, each represented by the median of its own summer-priced tariffs.

What to do with this

Your tariff sheet shows whether your utility prices by season, and which months count as summer. The calculator prices every current tariff your utility files across a full year at your usage, so a summer premium is already in the totals it compares.