Illinois gasoline prices jump 9.3 cents in a week, hit $4.32 per gallon average

Published 3:32 pm Monday, August 3, 2026

CHICAGO — Average gasoline prices in Illinois rose 9.3 cents per gallon over the past week, reaching $4.32 per gallon Monday, according to GasBuddy’s daily survey of 4,378 gas stations across the state.

Illinois prices are now 33.4 cents per gallon higher than a month ago and 90.2 cents per gallon higher than a year ago, GasBuddy reported. The cheapest station in the state was priced at $3.69 per gallon Sunday, while the most expensive was $6.99 per gallon, a spread of $3.30.

Nationally, the average price of gasoline fell slightly last week, dropping 0.8 cents per gallon to $4.05. The national average is up 28.5 cents from a month ago and 93.6 cents from a year ago, according to GasBuddy, which compiles its data from more than 11 million weekly price reports covering over 150,000 gas stations nationwide. The national average price of diesel rose 7.1 cents over the past week to $5.326 per gallon.

Illinois’ current average marks the highest price for this date in at least five years, according to GasBuddy historical data.

Patrick De Haan, head of petroleum analysis at GasBuddy, attributed the volatility to global instability affecting oil markets.

“Average gasoline prices were a mixed bag across the country last week as oil markets went on a wild ride, surging on geopolitical tensions before pulling back Sunday night after President Trump signaled a potential deal may be in the works,” De Haan said. He added that continued Ukrainian attacks on Russian oil infrastructure are driving up refined product prices even as crude oil eases, and that the national average could reach its highest level ever recorded for this point in the calendar year by later this week — though still below the all-time record set in 2022.

De Haan said motorists should watch developments in the Persian Gulf and Ukraine closely, as either could quickly alter the price outlook.