DENVER (KDVR) — Gas prices skyrocketed after the first full week of Russia’s attack on Ukraine.

Denver gas prices jumped 43.1 cents in the last week, according to GasBuddy.

The average cost for a gallon of gas in Denver was $3.69 on Monday. That’s up 99.1 cents over a year ago.

The nationwide average broke $4 a gallon on Sunday, the first time that’s happened since 2008.

In Denver, gas prices ranged between $3.31 and $4.29. Around Colorado, the cost for a gallon reached as high as $4.99.

These were the average gas prices on the Front Range and in Colorado as of Monday:

Denver: $3.69, up 43.1 cents in a weekFort Collins: $3.70 a gallon, up 38.4 cents in a weekColorado Springs: $3.73 a gallon, up 35.8 cents in a weekColorado: $3.73 a gallon, up 39.9 cents in a week

Coloradans could have it worse. In southern California, the cost for a gallon reached $6.65 in some places.

Oil and gas is Russia’s biggest export to the U.S.

Gas prices will continue to rise as seasonal demand grows, “with significant spikes possible in 2022 amid international uncertainty,” AAA predicted.

Calls have risen to cut off Russian oil and gas imports as its attack on Ukraine continues. That could pose a problem for the U.S. fuel supply.

The U.S. is the world’s largest oil producer, ahead of Saudi Arabia and Russia. But it’s also the world’s biggest consumer.

Mineral fuels are Russia’s top export to the U.S., with the country sending $13 billion worth of oil and gas in 2019.