Natural gas futures firmed Monday on expectations that continued colder-than-normal weather in the central and eastern U.S. would keep demand high for the heating fuel. Natural gas for February delivery settled up 5.9 cents at $4.427 a million British thermal units on the New York Mercantile Exchange. The 1.4% gain was the largest one-day rise since Dec. 19. Natural-gas prices have climbed from less than $3.50/mmBtu in early November, as continued cold weather has led to robust demand for indoor heating in homes and offices. About half of U.S. households use natural gas as their primary heating fuel, according to the Energy Information Administration. Unusually large amounts of natural gas have been withdrawn from storage in recent weeks. Inventories as of […]