US natural gas prices extended gains in after-hours trading Wednesday as forecasts for hotter weather pointed to stronger cooling demand from power generators, while expectations for a smaller-than-average weekly storage injection provided additional support.
The front-month Henry Hub contract and the continuous contract both rose by 3.27% to $2.999 per million British thermal units.
Higher US prices also drew support from a rally in European gas markets, Barchart reported. European natural gas futures climbed to a 3.75-year high Wednesday as concerns grew that disruptions to shipping through the Strait of Hormuz could persist amid an escalation in the US-Iran conflict.
However, most of Wednesday's gains were driven by expectations of increased cooling demand amid warmer US weather forecasts, Barchart said. Citing forecaster Vaisala, it said temperatures were trending hotter across the Midwest and eastern US for Sept. 7-11, and would shift even warmer across the Midwest for Sept. 12-16.
Hotter weather typically boosts power burn, or the amount of natural gas consumed by power plants to generate electricity, increasing demand for the fuel.
NRG Energy said power burn remained elevated at about 48.5 billion cubic feet per day Wednesday, roughly 20% above September 2025 levels. Gelber & Associates put Wednesday power burn at 48.3 Bcf/d.
Celsius Energy said its data showed power burn averaged 46.6 Bcf/d for the week ended Aug. 31, up 4.7 Bcf/d from the comparable week last year.
LNG feedgas demand held near 18.7 Bcf/d Wednesday despite softer nominations at Sabine Pass following Tropical Depression Edouard. G&A said there was no confirmed prolonged storm-related disruption at Gulf Coast export facilities, keeping LNG demand relatively strong as the storm moved inland.
Trading Economics said average gas flows to the nine major US LNG export plants increased to 18.3 Bcf/d in early September from 17.2 Bcf/d in August, as Cheniere Energy's Corpus Christi facility and Freeport LNG in Texas returned to full operations following maintenance.
Total natural gas demand in the Lower 48 states was 79.5 Bcf/d Wednesday, up 7.6% from a year earlier, according to BNEF.
Strong production, however, continued to limit the upside in prices. G&A estimated US natural gas production at 110.8 Bcf/d Wednesday, with Canadian imports at 5.9 Bcf/d, putting total supply near 116.7 Bcf/d.
Trading Economics said U.S. natural gas output averaged a record 111.5 Bcf/d in August, up from 110.7 Bcf/d in July.
Storage expectations ahead of Thursday's US Energy Information Administration report also supported prices.
Barchart said analysts expected a 32 Bcf injection for the week ended Aug. 28, below the five-year average build of 37 Bcf. G&A was forecasting a smaller 28 Bcf increase, compared with a 45 Bcf build in the same week last year, while analysts surveyed by The Wall Street Journal expected a 29 Bcf increase.
A smaller-than-average injection would signal that strong power-sector demand and LNG exports are drawing more gas from the market than is typical for this time of year, potentially keeping inventories tighter heading into the fall.