Average National Gas Prices At Their Highest Since March 2013

April has indeed been the cruelest month – if you're talking about U.S. gas prices.

AAA reports the national, average price of gas this week reached $3.70 a gallon, or the most expensive gas has been at the pump since March 20 of last year. Gas prices have also risen 13 percent, or an average of 42 cents per gallon, since early February. And for the month of April alone, gas prices were up an average of 14 cents per gallon nationally – the largest increase for April in three years.

“Drivers can’t seem to catch a break with gas prices rising nearly every day since February,” Avery Ash, AAA spokesman, said in a press statement. "Spring is generally the worst time of year to fill up the car, and high gas prices are hard on people hoping to take advantage of the warmer weather."

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One of the primary reasons behind the higher April prices is the annual, federally-mandated switchover from winter-blend to summer-blend gasolines, which has a May 1 deadline. Refineries also use the first quarter of the year – usually the quietest for demand – to undergo routine maintenance. These down periods can tighten oil and gas supplies.

And recent “glitches” at the BP BP refinery in Whiting, Indiana and the ExxonMobil XOM facility in Joliet, Illinois, as reported by GasBuddy.com, haven't helped gas inventories, either.

The good news – and there is some good news – is that gas prices are still less expensive than last year's average high of $3.79 per gallon. AAA expects that, as gas production increases for the summer driving season and more refineries come back on-line, drivers should see a decline at the pump.

"It is possible that gas prices may rise somewhat higher in the coming days," Ash continued, "but a little relief could be in sight. With any luck most of us will pay lower gas prices by the time everyone hits the road for Memorial Day."

In case you're keeping track, the highest gas prices this week in the “Lower 48,” according to AAA, were in San Luis Obispo-Atascadero-Paso Robles region of California, at $4.36 per gallon. The least expensive gas prices could be found in Great Falls, Montana, at $3.28 per gallon.