Gas prices on Thursday hit another record high, jumping two-tenths of a cent to reach a national average of $3.289 per gallon.

Regular unleaded was $3.168 a gallon on average at this time last month, and $2.70 a year ago. The price of crude oil has held above $100 a barrel, according to AAA.

The average price for diesel fell two-tenths of a cent to $4.023. Diesel averaged $3.681 a gallon last month and $2.865 a year ago, AAA reported.

The high price of diesel fuel has been a major concern for workers in the trucking industry, with some news media reporting murmurs of truckers going on strike.

California overtook Hawaii for the state with the most expensive gas. Prices for regular unleaded in California jumped to $3.663 per gallon. New Jersey was the only state to see gas prices below $3.10 a gallon.