Jacksonville drivers woke up Wednesday, Sept. 9, paying more than $4 a gallon for regular gasoline after an overnight spike of 21 cents.

Jacksonville gas prices surge overnight

AAA data shows the Jacksonville average surged from $3.89 per gallon on Tuesday to $4.10 on Wednesday, a 5.4% increase. News4Jax reported the local average is now about $1.03 above last September's $3.07 average. For Mandarin commuters filling up along San Jose Boulevard, the Duval County average applies, and individual stations may already be charging more.

Some stations are well above that average. Action News Jax reported drivers on Beach Boulevard were seeing $4.19 per gallon on Wednesday, 10 cents over the Duval County average.

Statewide and national averages also climb

Florida's statewide average jumped 18 cents to $4.07 per gallon, the highest level ever recorded after Labor Day, according to the Florida Times-Union.

The national average stood at $4.22.

Global oil surge tied to Iran conflict

The spike followed a sharp rise in global oil prices. Brent crude hit $100 per barrel on Wednesday for the first time since July after U.S. forces destroyed five Iranian oil tankers on Tuesday, according to USA Today. Gas prices nationally have risen 42% since the U.S.-Iran conflict began Feb. 28.

Oil flows through the Strait of Hormuz, a critical shipping lane, have fallen below 2 million barrels per day. That is down from roughly 8 million to 9 million barrels per day before fighting resumed Aug. 30, according to Rystad Energy data cited by Reuters.

AAA explains the price connection

AAA spokesperson Marie Dodds explained the connection in a Sept. 3 statement reported by FOX 13. "The conflict has sent crude oil prices dramatically higher," Dodds said. "Crude oil is that basic ingredient used to make a gallon of gas or diesel. So when the cost of your basic ingredient goes up — so does your end product."

Where to find the cheapest gas

Drivers hunting for cheaper gas can find some relief. The lowest-priced station in Duval County on Wednesday was Love's Travel Stop on Pecan Park Road at $3.72 per gallon, according to AAA. In St. Johns County, a Citgo on South Ponce de Leon Boulevard was listed at $3.71.

AAA recommends slowing down, keeping tires properly inflated and shutting off the engine when stopped for more than 60 seconds. The organization also says premium gasoline provides no added benefit unless the vehicle manufacturer recommends it.

Forecasts diverge on oil price future

Goldman Sachs researchers warned oil prices could reach $120 per barrel if Middle East shipping attacks intensify. Treasury Secretary Scott Bessent said prices could fall to between $40 and $50 per barrel once the conflict ends.