Need to fill up the tank but don’t want to drain the wallet in the process? You might want to think about hitting the gas station on Sundays, at least in 2026. That’s according to a new nationwide analysis from GasBuddy, which found that Sunday is the cheapest day of the week to buy gas in most of America. Remember: That’s most, not all. Alaska, Delaware, Indiana, Kansas, Montana, Ohio, Pennsylvania, South Dakota, and Wyoming are all exceptions to the rule.

Another trend that remains true for much of the country: From coast to coast, prices typically climb higher during the middle of the week. And even though there are some exceptions to this data, as well, there’s a single fact that applies to every single one of these 50 states: Per their findings, Sunday is no state’s worst day to fill up. Saturday’s the best in Kansas, Pennsylvania, South Dakota, and Wyoming, while Tuesday’s the best in Montana alone. 

The discount fill-up app’s report looked at daily statewide average gas prices over the past year and pinpointed the most consistent weekday pricing patterns. Across much of America, it looks like prices start going up on Monday, peak around midweek, and start going back down again heading into the weekend. That’s a steady weekly rhythm most of us can depend on. In most states, the difference between the lowest-priced day and the most expensive one can be anywhere from 4 to 9 cents per gallon. For motorists filling a standard 12- to 16-gallon tank, that difference is going to add up over time.

Most of us know to expect some modest fluctuations in gas prices from week to week. However, according to GasBuddy, some states actually experience much more dramatic price swings than others. It’s due to a pattern known as price cycling, and it’s most prevalent in states like Michigan, Indiana, Ohio, Florida, Texas, and some West Coast areas. There, prices often spike much more sharply on a given day before gradually declining over the next several days. In these places, the difference between the highest and lowest points in a weekly cycle can be way more dramatic: as much as 15 to 45 cents per gallon. Don’t forget that gas prices always add an extra 9/10 of a cent to add insult to injury.