DETROIT (AP) — Even with a major snowstorm hitting the Northeast last month, automakers are reporting double-digit U.S. sales increases for January.

GM says its sales rose 18 percent over last January. Ford and Nissan each posted 15 percent gains. And Chrysler says its sales rose 14 percent, for its best January since 2007.

January is typically a slow month for the auto industry. But this January was a big improvement over last year, when the polar vortex brought record-setting cold to much of the country.

Gas prices continued to fall in January, hitting a six-year low of $2.03 per gallon on Jan. 26, according to AAA. That gave consumers the confidence to choose bigger vehicles.

At GM, sales of the nine-passenger Chevrolet Suburban SUV more than doubled. Sales of the big Cadillac Escalade also more than doubled.