Paying more for gasoline in Kansas City? What to know about summer vs. winter prices

If you’ve stopped by the pump in the last few days, you may have noticed that gas prices are up in the Kansas City area.

The American Automobile Association (AAA), which tracks gas prices around the country, lists the current average price per gallon of regular gasoline in Kansas City at around $3.70 as of Monday morning — up from $3.50 just one week ago.

Statewide, Missouri’s gas prices are up 18 cents a gallon since last week on average, while Kansas’ are up 11 cents a gallon.

This recent bump is due in part to refinery outages that are increasing demand and driving up prices at the pump across the Midwest, petroleum analyst Patrick De Haan told The Star.

The squeeze in demand also comes at a time when refineries around the country are preparing for their seasonal switch between “summer gasoline” and “winter gasoline.”

Here’s what that means, and how it could impact the price of your next tank.

What’s the difference between ‘summer gasoline’ and ‘winter gasoline?’

As your favorite retailers bring back cold-weather recipes like pumpkin spice lattes or peppermint hot chocolate, you may not realize that your local gas station is doing the same thing.

It all has to do with the Clean Air Act, a 1990 rule established by the federal Environmental Protection Agency (EPA) to reduce air pollution around the country.

The act set limits on the amount of vapor that commercially available gasoline can produce during different times of year. Gasoline vapor contributes to ground-level ozone, a key ingredient in smog that can cause asthma and other respiratory conditions.

Since gasoline produces more vapor in hot weather, the EPA mandates a lower volatility for gasoline sold in the summer months than in the winter months.

The gasoline industry now produces low-vapor gas to sell between June 1 and Sept. 15 every year, and switches to a formula that vaporizes more easily during the rest of the year.

Winter gasoline’s higher volatility comes from highly-combustible “fillers” like butane, which make it cheaper to produce. That’s why a tank of gas is typically more expensive in the summer and cheaper in the winter, no matter where you live.

What’s causing the recent gas price bump in the Kansas City area?

De Haan told The Star that decreased production at three Midwestern oil refineries are limiting the supply of low-vapor “summer” gasoline.

One, in Minnesota, has been planning maintenance on its facility for months. But two other refineries — in Oklahoma and Illinois — are also experiencing unexpected outages.

Combined, these three shortages are increasing the demand for summer gasoline right before refineries make the seasonal switch away from it on Friday.

Since “winter” gasoline is cheaper to produce, the industry doesn’t typically make much more “summer” gasoline than it thinks it can sell before Sept. 15.

This is making it more difficult for Midwestern gas stations to get the low-vapor stuff they need to last the rest of the week, driving up prices at the pump.

When will gas prices go down again?

Prices are already decreasing slightly in the Midwest as other refineries step in to fill the demand — and De Haan said the switch to winter gasoline is likely to bring drivers even steeper discounts by early next week.

“There should be a very drastic change in the supply situation once we roll over to winter gasoline (on Friday), because the supply of winter gasoline should be in much better shape,” he said.

“By this time next week, every station should be in a trend of lowering prices.”

He added that while regional fluctuations in gas prices can be frustrating, drivers should remember that these adjustments are being caused by refineries — not the government.

“This is not a political situation,” he told The Star. “This spike in prices is not happening everywhere, and at a federal level to blame somebody for what’s happening in one state but not another is really a lack of understanding of what is happening.”

Instead, gasoline consumers should prepare for a shrinking number of oil refineries as demand for gasoline drops, potentially leading to these types of outages having a more widely-felt effect on gas prices.

“We probably had double the number of refineries in the country 30 years ago. So when they go down, it’s more problematic now than it used to be,” he said. “The heyday of gasoline consumption is behind us.”

Do you have more questions about the price of gas or other necessities in the Kansas City area? Ask the Service Journalism team at