U.S. retail sales dropped by the most in nearly two years in January, likely because of frigid temperatures and moderation following hefty gains in the past four months, suggesting a sharp slowdown in economic growth early in the first quarter.

With consumer spending making up two-thirds of economic activity in the U.S., the sales numbers indicate potentially weaker growth for the first quarter.

U.S. retail sales fell more than expected in January, dropping a seasonally adjusted 0.9% from December to $723.9 billion, the Commerce Department said. Economists surveyed by The Wall Street Journal had expected a drop of 0.