The westerly wind usually blows it toward the US side where the moisture wraps every inch of the landscape in white, National Weather Service meteorologist Steven Welch said.

With a deep freeze stretching from south Texas to Canada and from Montana through New England, the surreal scenes have played out across a wide swath of the US.

Fountains froze in Texarkana, Arkansas, New York City's Bryant Park - and even Savannah, Georgia, where January's average high is -16 C. The thermometer read -1 C on Tuesday, cold enough for icicles to dangle from the ornate wrought-iron fountain in Forsyth Park.

Chunks of ice floated down the Mississippi River and Lake Michigan made "ice balls" with its rolling waves.

Forecasters warned of hazardous travel from the southeast to New England through Friday, with the worst expected from the Carolinas to Maine. The bitter cold will linger into the weekend.

Tim Partin of Williamsburg, Kentucky, was in Niagara Falls on business when he decided to take in the scenery. "It really is pretty," he said.

A mix of freezing rain, sleet and snow was forecast to fall in an area from northern Florida to South Carolina, which could snarl transport.

AP - Reuters