GasBuddy’s survey of 201 stations in Modesto shows gasoline prices in Modesto have risen 16.4 cents per gallon in the last week, averaging $5.76/gallon as of Monday, Sept. 14. Prices in Modesto are 41.4 cents per gallon higher than a month ago and stand $1.43/gallon higher than a year ago. The national average price of diesel has increased 31.6 cents compared to a week ago and stands at $6.18 per gallon.

According to GasBuddy price reports, the cheapest station in Modesto was priced at $5.36/gallon while the most expensive was $6.79, a difference of $1.43/gallon. The lowest price in the state was $4.29 while the highest was $7.89, a difference of $3.60/gallon.

The national average price of gasoline has risen 17.2 cents per gallon in the last week, averaging $4.25/gallon on Sept. 14. The national average is up 19.0 cents per gallon from a month ago and stands $1.14/gallon higher than a year ago, according to GasBuddy data compiled from more than 11 million weekly price reports covering over 150,000 gas stations across the country.

Neighboring areas and their current gas prices: Stockton - $5.74/gallon, up 14.1 cents from last week’s $5.60; Oakland - $5.99, up 12.2 cents from $5.87; and San Jose - $5.94, up 9.6 cents from $5.84/gallon.

“Average gasoline and diesel prices rose in every state over the last week as geopolitical tensions escalated on multiple fronts, with friction between the U.S. and Iran, new hostilities in the Red Sea, and the shutdown of Saudi Arabia’s East-West pipeline all combining to jolt prices sharply higher,” said Patrick De Haan, head of petroleum analysis at GasBuddy. “While most of the country transitions to cheaper winter-blend gasoline this week, the scale of ongoing geopolitical escalations makes meaningful price relief unlikely in the near term. Motorists should brace for continued volatility ahead.”

Historical gasoline prices in Modesto and the national average going back five years show the highest Modesto price of $5.27 was recorded on Sept. 14, 2022 and the lowest of $4.28 was on Sept. 14, 2021. Highest U.S. average of $3.84 per gallon was on Sept. 14, 2023 and the lowest of $3.12 was Sept. 14, 2025.

GasBuddy, a PDI Technologies company, is the most authoritative source of station-level fuel pricing data, updating averages 288 times daily from the broadest mix of inputs— spotter reports, direct station integrations, and transactional data.