HOUSTON, Jan. 17 (Xinhua) -- The Arctic air mass that blew through Houston, Texas earlier this week brought freezing rain, sleet and frigid temperatures to the city, causing the mercury Wednesday to dip to a 22-year low.

Houston officials shut down schools and businesses for two straight days as temperatures plummeted to minus 7 degrees Celsius on Wednesday, which marked the lowest since Jan. 8, 1996.

The U.S. National Weather Service (NWS) downgraded the winter storm warning issued for Houston to a winter storm advisory late Wednesday. Houston-area schools and businesses are expected to reopen on Thursday.

The coldest Jan. 17 in Houston was recorded in 1930, when temperatures dipped to minus 9 Celsius, according to the U.S. NWS.

Houston's average low for January is 7.2 degrees Celsius.