Why Do Gas Prices Rise During Summer Months?

May 10, 2013

Scores of travelers depend on their vehicles to reach their summertime destinations, and many drivers have had to accept annual jumps in gas prices when budgeting for road trips. While paying more money at the pump may not be avoidable, we can better understand WHY we’re paying more during the summer season.

One established factor in the summer season is the economic concept of supply and demand. As more people fill cars, boats, motorcycles, and jet skis with gasoline, the demand for fuel increases. This places a higher premium on shrinking supplies, thus raising gas prices.


But there are other less-apparent factors that influence annual price bumps. Among those include:

~  Refineries shutting down during spring months for maintenance

~  Natural disruptions, such as hurricanes, impacting transport and damage refineries

~  Fuel grades purchased in summer months are different from grades purchased during the rest of the year

Perhaps the greatest factor that influences rising gas prices in the summer months involves a change in fuel supply, known as the seasonal gasoline transition, which occurs twice every year in the U.S. This seasonal switch is part of the Reformulated Gasoline Program (RFG), which was established from the Clean Air Act Amendments, aimed at reducing pollution and smog during the summer season.

Most consumers don’t notice a difference, outside of higher fuel costs, but the summer-grade fuel they purchase actually has altered ingredients. This fuel contains different oxygenates (fuel additives) to give it a higher Reid Vapor Pressure, which allows evaporation to occur more easily than with winter-grade fuel. The result is a fuel that burns cleanlier, thus compensating for a limited oil supply, and emits fewer pollutants. This is an important consideration at a time of year when increased temperatures boost the formation of the ozone layer, and pollution becomes a greater focus of concern. Winter-grade fuel uses more butane, which is inexpensive and plentiful, and brings fuel prices back down during the rest of the year.

Paying a premium at the pump has become a summertime tradition, much like barbequing or going to the beach, but no matter the fuel management strategy, consumers can appreciate knowing the fuel they purchase is better for the environment. In fact, the Environmental Protection Agency reports that, "roughly 75 million Americans breath cleaner air today due to [the seasonal fuel] program.”