MIAMI — Adverse weather conditions in the Central and Eastern portions of the United States weighed on U.S. and Canadian comparable sales at Burger King Corp. in January and February.

In the two months ended Feb. 28, company comparable sales growth in the United States and Canada fell 6.1% in constant currencies, which compared with 2.4% growth in the same period of 2009. System comparable sales growth in the two months fell 8.2%, which compared with growth of 3.1% a year ago.

Overall, total company comparable sales growth in the two months was down 5.8%, which compared with 0.9% sales growth in the same period of 2009.

“U.S. and Canada January sales were impacted by adverse weather conditions, which worsened in February, resulting in lower-than-anticipated sales,” said John W. Chidsey, chairman and chief executive officer. “However, we have seen improvement in sales with positive traffic at our company-owned restaurants in the U.S. and Canada during the first week of March, compared to January and February, as the impact of weather has become less significant.”

Burger King said it will continue to feature its value menu, including the launch of the Buck Double beginning in April. Later this month, the company said it will introduce its BK Breakfast Muffin sandwich and BK Breakfast Bowl. The product introductions come in advance of the new U.S. breakfast platform launching later in the year, Burger King said.