Drivers in the territory looking to fill up their tanks ahead of the long weekend have experienced a dramatic surprise at the pumps.

Gas prices in Whitehorse have jumped nearly 10 cents a litre from the beginning of the month.

The cost of a litre of regular unleaded fuel rose from 1.279 at the end of April and early May to 1.379 as of May 15, according to Bob Collins, an energy resources analyst with the Department of Energy, Mines and Resources.

The data are collected every two weeks around the territory by the Yukon's Bureau of Statistics.

Gas prices shot up all around the territory. The price in Dawson City went from $1.476 on April 17 to $1.537 on both May 1 and 15.

The cheapest place to fill up in the territory? Ross River, where gas is $1.353.

The Yukon generally has higher gas prices than much of the rest of the country.

According to Mike Erwin, president of M.J. Erwin and Associates, a petroleum research group, the average cost of unleaded gas in the territory last year was $1.33 a litre.

The national average is $1.275.

Erwin said much of western Canada is experiencing high gas prices in part because of some recent refinery outages.

Most of the territory's gas comes from Edmonton.

The wholesale price of gas coming out of Edmonton has been getting progressively higher every day — all month.

On May 2, the wholesale price was 78.8 cents per litre. That has risen every day to 87.9 cents on the 15th and 89.3 cents Thursday morning.

Higher mark-ups also happen here because of the smaller volume of customers, Erwin said.

"When you have that volume of customers, there is an increased cost to keep businesses running.”

In Whitehorse, the highest gas prices ever presented themselves on July 16, 2008, when the average price hit $1.461.

Dawson City holds the territory-wide all-time record. On Aug. 13, 2008, regular gas prices hit $1.717, according to the territory's statistics bureau.

Both Erwin and Collins credit the fluctuating market and various market factors with leading to the rising cost.

The territorial gas tax is the lowest in the country — 6.2 cents per litre of gas and 7.2 cents per litre of diesel. That charge is not influenced by the price of gas.

But individual Yukoners are not the only ones who have to deal with the higher prices. The Department of Highways and Public Works estimates it will spend $6,500 more a month on gas while the prices are at this level.

Spokesperson Kendra Black says this covers the department's 515 fleet vehicles, such as light-duty trucks and passenger vehicles. It does not include road maintenance trucks.

Because they buy in bulk, the department receives a four cent per litre discount on its gas, Black said.