Natural gas futures soared over the summer months, driving up costs for utilities that bought gas ahead of the fall months and then passed along the hikes to consumers, new federal data show. More inflation lurks as winter weather and heating demand near.

The U.S. Department of Labor on Thursday (Oct. 13) said overall consumer inflation broadly held near a 40-year high – the consumer price index increased 8.2% in September from a year earlier and 0.4% from the prior month. Annual inflation hit a peak this year at 9.1% in June.

Energy prices that jumped 19.8% in September from a year earlier continued to drive the headline number. However, some recent easing helped to draw down overall inflation. Cumulative energy inflation month/month declined 2.1% in September after falling...