Californians continue to pay the highest average fuel prices in the country, and this week’s $0.17-per-gallon increase pushed the state average above the $6 threshold.

Gasoline in the Golden State averaged $6.01 per gallon on April 30, the American Automobile Association (AAA) reported. Despite the price surge, the state’s average cost per gallon of gasoline is still below the record high of $6.43 per gallon in June 2022.

The average price for diesel fuel in California remained flat week over week at $7.48 per gallon and is down slightly from its all-time high of $7.74 per gallon recorded on April 9, AAA noted.

Californians’ pain at the pump is due to a combination of high state and federal taxes and strict environmental regulations that routinely push fuel prices well above national averages, the U.S. Energy Information Administration (EIA) said.

Average per-gallon fuel prices were highest in California’s North Bay Area cities of San Rafael at $6.26, Napa at $6.23, and Santa Rosa at $6.20—prices that were a touch higher than much denser Bay Area metropolitan areas such as San Francisco ($6.19) and San Jose ($6).

The San Francisco Bay Area led all metro regions in the average cost of diesel fuel. In San Francisco, the average price for a gallon of diesel was $7.74, followed by Santa Rosa at $7.72 and San Rafael at $7.71.

Retail fuel prices are elevated throughout the West Coast, AAA reported. Gasoline averaged $5.57 in Washington and $5.15 per gallon in Oregon. Other states above the $5 per gallon average threshold include Hawaii at $5.64 and Nevada at $5.12. States with the highest average diesel fuel prices per gallon include Hawaii at $7.15, Washington at $6.84, and Oregon at $6.23.

Nationally, fuel prices jumped by $0.27 to an average of $4.30 per gallon, AAA reported. Gasoline prices are at their highest level since late July 2022, when they averaged $4.27 per gallon after hitting an all-time high of $5.01 in mid-June.

Gas prices spiked because of reduced gasoline production and increased demand. According to the EIA, gasoline demand increased from 9.055 million barrels per day to 9.104 million, while production declined to 9.887 million barrels per day.

The ongoing war in Iran and closure of the Strait of Hormuz pushed oil prices past the $100-per-barrel threshold on April 30, with West Texas Intermediate crude touching $110 per barrel. According to the EIA, U.S. crude inventory stood at 459.5 million barrels—1 percent higher than the five-year average for late April.

Fuel prices are likely to remain elevated as long as oil flows through the Strait of Hormuz remain impacted, the EIA stated in early April. The EIA expects Brent crude to peak at $115 per barrel in the second quarter before dipping below $90 per barrel by the fourth quarter and averaging $76 per barrel in 2027. However, those predictions are heavily predicated on the cessation of the conflict in the Middle East, which continues to disrupt energy prices across the globe, the EIA noted.

Gas prices remain at their lowest throughout the Midwest. Oklahoma led the nation with the lowest average price per gallon at $3.70, followed by Kansas and Georgia at $3.75. The lowest diesel fuel averages were $4.75 in Oklahoma, $4.79 in Kansas, and $4.86 in Nebraska.