U.S. natural gas surged Tuesday to the highest level in nearly 14 years as Russia’s invasion of Ukraine wreaks havoc on global energy markets.

Henry Hub prices jumped more than 9% to $8.14 per million British thermal units (MMBtu) during morning trading on Wall Street, the highest level since September 2008.

Campbell Faulkner, senior vice president and chief data analyst at OTC Global Holdings, said the move was due to a “flurry of tighter market conditions,” including the European Union considering a sixth round of sanctions against Russia that could include the nation’s energy complex.

Additionally, production is down in the U.S., and gas in storage is 21% lower than at this time last year.

“Higher power burn this summer with zero coal gas…switching will reduce the amount of spare gas for storage infill which is pushing prices up in a classic commodity cycle (backwardation) to get gas into the market now,” he added.

Over the last two sessions, natural gas prices have jumped more than 12%. The surge follows a nearly 30% gain in April. The swift upward price action, which is also being fueled by surging demand for U.S. liquified natural gas, is adding to inflationary pressures across the economy. Consumers’ electricity bills are rising as utility companies pass along their higher input costs.

EBW Analytics also pointed to changing weather patterns as fueling demand for natural gas as warmer temperatures usher in air-conditioning season.

“A faster-than-expected turn hotter, however, is the principal bullish driver as traders jump on early-season heat in Texas—and any further weather model shifts hotter could set up a challenge of recent highs,” the firm added.

Energy was the top-performing S&P 500 group Tuesday, advancing more than 1%.