(WZZM) -- Once again, everybody is asking why gas prices are spiking up to $4.15 a gallon over the weekend. According to Patrick DeHaan from GasBuddy.com, prices will be unstable all summer long.
An already tight supply of gas in the midwest got worse when an oil refinery was unexpectedly unable to meet demand and had to go elsewhere to buy oil for customers.
"While prices are at $4.15, some stations have started to roll back prices in Grand Rapids, some on the low side at $4.07," said DeHaan. "Prices may continue to tiptoe lower in the next day, but beware, the market is very volatile, we could see another price spike in the near future."
DeHaan added that the root cause of higher prices is the closing and regulation of refineries, leading to tighter and tighter oil supplies.
WZZM checked the government website for the U.S. Energy Information Administration, which verified DeHaan's explanation.
In 1982 there were 26 refineries in Michigan, Illinois, Indiana and Ohio. In 1992 it was down to 18 refineries. That dropped to 12 in 2002, and in 2012 there were a total of 11 refineries in operation in all four states.