Last month, the electricity prices of New York City hit record highs causing many Con Ed customers’ bills to spike more than 20 percent.

The utility blames the boost on rising prices for natural gas, which powers most electricity generators. Paralleling, natural-gas prices rose because the cold weather drove up demand for gas heat.

“It’s astronomical!” said Jerilynn Mabry of Harlem, who complained to the AARP, which is lobbying for better regulation of the state’s utility industry.

Mabry’s bill for January was $87.36, a 17 percent jump from her December bill of $74.74. “Usually, my winter bills are much less — $46, $36,” said Mabry, a 64-year-old retiree. “It’s amazing this year.”

Leigh Jones, another Harlem resident, saw her bill jump from $60 for December to $101 for January. “I was definitely surprised,” said the 40-year-old college professor.

Jones says Con Ed wrongly claims she increased her electricity use. But she noticed in the January bill’s fine print she’s paying a supply charge of 18.8 cents per kilowatt hour, far higher than usual for this time of year.

The supply charge, which covers the cost of actually generating electricity, is the source of this winter’s power-bill misery. Con Edison’s electricity supply charges are adjusted daily, the company says. The number that shows up in bills is an average of the daily prices.

A Con Ed customer with a billing period from Dec. 30 to Jan. 30 paid an average supply charge for the month of 23.1 cents per kilowatt hour — a shocking 83 percent boost over the 12.6-cent charge during the same period last year.

That price is the highest in at least five years and even tops the price spikes Con Edison customers see in the summer air-conditioning season.

The company says a typical New York City customer’s January bill for 300 kilowatt hours was $118, a boost of $21, or 22 percent, over last year.

To combat rising electricity supply costs, New York City residents can switch electricity suppliers. The process only takes a few minutes. Simply have a recent utility bill handy and browse through a variety of providers at ElectricityRates.com. Saving money on utility bills has never been so easy!