Why your summer electric bill spikes

It is almost never one thing

People tend to look for a single dramatic explanation for a surprising bill. In practice a summer spike is usually three or four modest factors compounding, none of which would be alarming on its own.

That is also why it feels sudden: the factors accumulate quietly over a season and only become visible when the weather makes the system work hard enough for them to matter.

The usual contributors

The thermostat setting is the largest lever most people control directly. Every degree lower is a longer run time, all day, for the whole season.

A dirty filter means restricted airflow, which means the system runs longer to achieve the same temperature. The bill reflects run time, not intent.

Attic heat gain is the invisible one. A poorly insulated, poorly sealed attic bakes all afternoon and pushes heat down into the living space, which the air conditioner then has to remove.

And equipment that has not been serviced simply does not perform the way it did new — dirty coils, low airflow and worn components all cost efficiency.

What to do about it in what order

The filter is free to check and the cheapest thing to change. Do that first.

The thermostat schedule is next, and costs nothing: a setback while the house is empty removes hours of run time without touching comfort when it matters.

The attic is a real project with a real payback, and it is worth measuring before spending — see the guide on where houses actually lose heat.