The pain at the pump kept getting worse for Americans last week as the retail price for gasoline shot up an average 9 cents to the highest level since October, the government said on Monday.

The national average price for regular unleaded gasoline rose to $2.59 a gallon, up 26 cents in the last month and 37 cents higher than a year ago, based on the federal Energy Information Administration's weekly survey of service stations.

Click here to visit FOXBusiness.com's Energy page.

Click here to visit FOXBusiness.com's Autos page.

Prices soared more than 11 cents a gallon in the last week in Chicago, Houston and San Francisco, the EIA said.

The Energy Department's forecasting arm said two weeks ago that gasoline prices had hit a short-term peak of $2.50 a gallon. That appeared to be the case after pump prices fell about about half a penny the following week.

However, the new jump in fuel costs mirrors a rise in crude oil prices. The price of oil accounts for about half the cost of making gasoline.

The price of U.S. crude for delivery in May hit $67.90 a barrel on Monday at the New York Mercantile Exchange, the highest mark since Feb. 1.

Motor fuel prices are also rising as gasoline demand increases with the approach of the busy summer driving season.

The EIA is also worried about local gasoline supply disruptions this summer as oil refiners switch from using the water-polluting fuel additive MTBE to corn-based ethanol when making gasoline.

In the EIA's latest weekly survey, the West Coast had the most expensive regional gasoline, with the price up 6.3 cents at $2.67 a gallon. Los Angeles topped the survey of cities, with gasoline up 6 cents at $2.78 a gallon.

The Rocky Mountain states had the cheapest gasoline at $2.42 a gallon, up 2.6 cents. Among major cities, Denver had the most affordable pump price at $2.50, up 3.3 cents.

The EIA report also showed prices, rounded to the nearest penny, up 11.3 cents at $2.76 in San Francisco; up 6.4 cents at $2.72 in Miami; up 12.8 cents at $2.67 in Chicago; up 4.4 cents at $2.58 in Seattle; up 12.2 cents at $2.57 in Houston; up 9.8 cents at $2.57 in New York City; up 8.2 cents at $2.55 in Cleveland and up 10.4 cents at $2.51 in Boston.

Separately, the average diesel fuel price paid by truckers jumped 5.2 cents last week to $2.62 a gallon, up 31 cents from a year earlier and the highest level since early November, the EIA said.

Truckers on the West Coast paid the most for diesel at $2.75 a gallon, up 5.5 cents. The Midwest region had the cheapest diesel at $2.58 a gallon, also up 5.5 cents.

Click here to visit FOXBusiness.com's Energy page.

Click here to visit FOXBusiness.com's Autos page.