API said the delivery of petroleum products, a measure of demand, declined 0.6 percent in February to 18.5 million barrels per day, the lowest average for any February since 1998.
API Chief Economist John Felmy said the cold weather was suppressing demand for petroleum products like gasoline.
"Cold weather tends to have a dampening effect on the economy, which helped reduce demand for many types of fuel in February," he said in a statement Thursday.
API said demand for gasoline declined 0.2 percent from February 2013, though it was up 1.1 percent from the previous month. January's gasoline demand of the equivalent of 8.4 million barrels per day, however, was a 13-year low for the month.
API said crude oil production in February increased year-on-year, but was 0.8 percent lower than in January. Crude oil imports rose 1.7 percent from February 2014 to 7.4 million barrels per day, though total imports of petroleum and petroleum products were down 2.3 percent year-on-year to the lowest level since 1996.
The National Weather Service says the average temperature for northern states from Montana to New York should be below average through June.