American households are enduring the longest streak of double-digit increases for monthly natural gas and electricity bills in decades, adding stress to cash-strapped budgets already hurt by widespread inflation, according to the U.S. Bureau of Labor Statistics.

Gas bills in September were about 33% higher than a year earlier to chalk up an 18th consecutive double-digit percentage gain, according to Labor Department data. That’s the longest streak in more than three decades, when a 58-month run of such gains ended in September 1983. Electric bills, which rose 15.5% last month, are on a seven-month streak of double-digit gains, the longest run in 16 years.

U.S. heating bills are poised to be even costlier, given signs of soaring oil and natural gas prices and cooling temperatures ahead of winter along with disruptions exacerbated by a European energy crisis and Russia’s war in the Ukraine. Natural gas is the key fuel for many U.S. power plants and homes that rely on oil for heat – such as in the Northeast – may be hit even harder by rising costs.