The national average diesel price has dropped below $4 a gallon for the first time since August, falling 3 cents to $3.98 a gallon for the week ended Nov. 12, according to the Department of Energy’s Energy Information Administration. The price is nearly identical to the same week in 2011, when the national average was $3.973. 

The average diesel price rose in all East Coast regions — New England, Central Atlantic and Lower Atlantic — and the West Coast less California region but fell in all others. The largest decrease was in California, where the average price dropped 6.5 cents to $4.16 a gallon. 

The New England area — which was hit by Hurricane Sandy two weeks ago — had the highest average price at $4.198 a gallon, while the Gulf Coast region had the lowest price, $3.875. 

The price in all but three regions — the Lower Atlantic, Midwest and Gulf Coast — remained above $4 a gallon.