Gas storage sites across the European Union are now about 52% full, as Europe's race to refill natural-gas stockpiles has become increasingly challenging since the Iran war drives up prices, making it less profitable for traders to buy and store fuel ahead of winter.

The conflict has severely disrupted flows through the Strait of Hormuz, which used to carry around 20% of global liquefied natural gas flows, while Iranian attacks have wiped out 17% of Qatar's LNG export capacity. European gas prices have jumped more than 70% since the war started.

Injection rates are running below last year's pace and the 10-year summer average, raising concerns that some countries could struggle to rebuild reserves. "Europe is on track to enter winter with its lowest gas storage buffer since the 2022 energy crisis," said Natasha Fielding, head of gas and LNG pricing at Argus.

The EU eased storage rules, allowing countries to target at least 80% of capacity by early November under difficult market conditions, instead of the standard 90% requirement. Europe is past the midpoint of the refill season—which runs from April 1 to Nov. 1—leaving roughly three and a half months to rebuild inventories.