Average diesel prices rose by 6.5 cents, increasing to $4.06 per gallon as of Monday.
The increase meant the fuel only had temporary relief on April 1 when it fell to below $4 per gallon, according to data from the U.S. Energy Information Administration.
The sample covers about 73,000 service stations and 9,500 truck stops in the contiguous U.S.
The Gulf Coast region, which includes southern U.S. border states from New Mexico to Alabama, saw prices rise by 9 cents to reach $3.76 per gallon. That was the second-highest uptick.
A group of Western states of Arizona, Nevada, Oregon and Washington experienced the highest average price increase for the period, rising 11 cents to $4.26 per gallon.
But the New England region, consisting of Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont, had prices remain at around $4.31 per gallon.
But lower fuel prices are no April Fools’ joke. This year, diesel prices were slated to decline to a $3.92 annual average, down from last year’s $4.21, according to an EIA short-term forecast. Next year, that could further drop to $3.85.