A winter storm has wreaked havoc across much of the US, causing blizzards, subfreezing temperatures and leaving more than 800,000 customers without power across five states. Michigan alone has reported 680,000 power outages. The storm has also caused significant travel disruption, with more than 2,000 US flights cancelled or delayed as of Thursday morning, according to FlightAware data. Meanwhile, other parts of the country are experiencing record high temperatures, with Washington DC forecast to reach 80F (26C) on Thursday - a February high not seen since 1874. Despite this, the northern states have been hit with blizzards, prompting the closure of schools, businesses and even state legislatures. In southern California, a winter storm warning was issued, with residents advised to brace for unusually cold temperatures, blistery winds and snow. In Canada, parts of southern Ontario were blanketed in snow, with ice pellets and freezing rain forecast for overnight.