All Houston airports will reopen Wednesday after shutting down on Jan. 21 as a winter storm barreled through South Texas.

Even though the airports are back open, there are still about 500 flights between Bush and Hobby airports that have been canceled on Wednesday.

A rare winter storm churned across the U.S. Gulf Coast on Tuesday, breaking snowfall records more than a century old in a southern region where flurries are unusual, as much of the United States remained in a dangerous deep freeze.

A rare frigid storm charged through Texas and the northern Gulf Coast on Tuesday, blanketing New Orleans and Houston with snow that closed highways, grounded nearly all flights and canceled school for more than a million students more accustomed to hurricane dismissals than snow days.

STORY: A once in a century winter storm is churning its way across the U.S. Gulf Coast, where snow flurries are rare.The National Weather Service said 31 million people were under a snowstorm warning on Tuesday - from southern Texas east through Georgia and north to the Carolinas and into Virginia.