U.S. natural gas prices more than doubled since the start of the year, and this summer’s air conditioning season could send them soaring by at least another 25%.

In the futures market, gas prices surged 4% Tuesday as hot spring weather in the southern U.S. pressured a market that has already been concerned about tight supplies. The forecast points to warmer weather across the south to continue.

“In the last month, there has not been a meaningful uptick in U.S. lower 48 states production,” said Matt Palmer, senior director North American natural gas at S&P Global Commodity Insights. “You’re seeing exports running full out on LNG; power burn from the power sector is really strong and layer in the heat we’re seeing and the expectation that the southern tier of the continent in May and June will see well above normal temperatures. That’s a recipe for higher prices.”

Natural gas futures were trading at about $8.30 per million British thermal units [mmBtu], up 137% for the year. A heat wave is expanding in the South, with temperatures above 100 degrees in some places. According to the National Weather Service, high temperature records are forecast to be tied or broken this week in Texas, Oklahoma and Louisiana.

The higher natural gas prices are hitting U.S. businesses and consumers at a time when other energy prices are surging with gasoline and record diesel fuel at records. Palmer said utilities that normally switch to coal for power when natural gas prices rise are finding that coal is even more expensive — the equivalent of $9 to $10 gas.

“The likelihood of prices in the double digits this summer is getting stronger by the day,” Palmer said.

While Russia’s invasion of Ukraine has sent Europe’s gas prices sharply higher, U.S. prices have edged up as well. Russia was supplying about a third of Europe’s gas.

U.S. prices, however, are not directly linked to the global market, even as the country sends about 15% of its gas production overseas in the form of liquified natural gas. European prices are about four times higher for LNG.

U.S. production fell sharply during the pandemic, and while it has restarted, it’s been growing slowly. In February, monthly production was 115.2 billion cubic feet per day, down from 118.7 BCF in December, according to the latest government monthly data.

“We’ll be topping $10 for sure. I would put $12 to $14 as the upper band,” said John Kilduff, partner of Again Capital. “This is a commodity that trades parabolically a lot. It’s no stranger to parabolic moves up and down. It’s incredibly volatile, and it also has the ability to reset. We could get to $10 or $12 and if you have a cool August, then you could be down below $8 again.”

Supply is tight in the U.S. market. The amount of gas in storage has been at an unusually low level, and cold spring weather followed by the heat wave has created more demand than normal at this time of year. That has made it more difficult to build inventories. Some of the gas that would be set aside for next winter is being used.

Kilduff said storage levels are 18% lower than last year and 16% lower than the five-year average. “Now you have the added pressures coming from LNG exports that are meaningful,” he said. “By meaningful, I mean it’s holding the U.S. back from getting wildly oversupplied or at high levels of storage for gas that would crush the price.”

Kilduff expects that 90 BCF of gas was injected into storage last week. The Energy Information Administration issues its weekly report on supplies Thursday.

“We’re starting off in a big hole,” he said. “We need to be like squirrels putting acorns away, and to the extent we have a heat wave, that retards the flow and underpins the price. You need to see triple digit injections.”

The warmer weather has been expected, but Bespoke Weather said that models “are growing more adamant about the return of stronger heat as we end the month and head into at least the start of June.”

Bespoke said total gas demand over the next 15 days is expected to run above normal. “This is likely the base state we will have for the summer season, given the persistence of La Niña, where we are skewed hotter than normal, with occasional variability back to just near normal at times,” the firm noted in its Tuesday comments.

Analysts said the gas market is typically quiet at this time of year, but Kilduff said the price action this week could be a harbinger of what the summer could be like if warmer than normal weather persists. He said the gas price was also supported by developments over the past weekend, when the Electric Reliability Council of Texas asked consumers to conserve electricity after six power plants went down unexpectedly.

Kilduff said power issues in Texas could impact oil and gas production if they recurred or became persistent.

“Normally, this is a pretty calm time for the energy markets,” said Rob Thummel, senior portfolio manager at TortoiseEcofin. “The month of May is usually pretty sanguine. … I guess it’s an early dose of summer. If we continue to see hot weather, that is likely to have the same effect as extremely cold weather. It’s going to have an impact.”

“Normally the release valve is coal. It’s just not there right now. …The consumer is kind of at the mercy of mother nature at this point for the summer,” Thummel said.

Thummel said the futures market is predicting gas will stay in the $8 range for nearly a year before falling below $5 again next April. He said he views the price as too high, given the state of the industry.

“$5 is probably better reflective of the current environment. We probably have a $3 or higher geopolitical risk,” he said.

Thummel said that U.S. production is growing, and companies with pipelines such as Kinder Morgan are expanding capacity from the Permian basin area in Texas.

The U.S. intends to send more natural gas to Europe to help compensate for the lack of Russian gas, but both export and import capacity have to be expanded. Thummel said exports should rise to about 20% of U.S. production over the next couple of years.

That should also help support U.S. prices.

“Last year at this time [the price] was under $3,” said Kilduff. “In the last couple of years, $1.50 was the rock bottom price you would get for a short amount of time.”