Yes, summertime, but also “my light bill will be higher than usual” season. However, a power company recommended that everyone should be using the 20-degree rule this summer.

Anthony Cook with Alabama Power said that everyone should keep their thermostat at 80 degrees when it’s 100 degrees outside. He said the rule is based on industry standards for the way most air conditioners are designed.

Cook said your AC unit will typically lower the temperature in your home about 20 degrees from what the temperature is outside. This means if it’s 100 degrees outside, most homes will only get down to around 80 degrees, WBRC reported.

So when you’re setting your thermostat while you’re home or away, you’ll want to keep this in mind.

Cook says you can set your thermostat for a lower temperature but it might not help much and you’ll end up spending more money in the long run.

“What it’s going to do is it’s going to continue to run in order to try and reach the temperature of where you set it but it really won’t get it beyond that 20-degree mark and so you’re gonna be wasting energy, which in turn wastes money.”

Cook said you should also change out your air filters often, which will help your unit run at peak efficiency.