Storms move on, cold air slides in NEW: Power restored to 100,000 customers in Toronto, electric company official says New York City will get steadily colder after reaching a record-breaking 71 degrees on Sunday (CNN) -- Thousands of Ontario, Canada, residents made do without power Monday in the aftermath of storms that toppled trees and brought down power lines. Meanwhile, residents in the upper Midwest prepared for bitter cold wind chills. More than 300,000 customers remained without electricity Monday across Ontario, including 200,000 in Toronto, officials reported, in the wake of what Mayor Rob Ford called one of the worst ice storms to hit the city. Still, the city was functioning and conditions were "not even close" to warranting an emergency declaration, he told reporters Monday. My caution continues to be my caution. Let's really plan for the worst," Haines said Monday evening. I am encouraged in the progress we have made today, obviously, with well over 100,000 customers being restored today. Ford said 100 trucks from other cities were on their way to Toronto to help restore power to more people. Toronto had opened more than a dozen warming centers some were expecting up to 300 people, officials said. In the United States, areas that had been as warm as the 70s on Sunday began a slide into frigid territory as Canada sent some of that cold air sliding across the eastern United States. Dangerously cold wind chills were on tap in parts of Kansas, Nebraska, South Dakota, North Dakota, Minnesota, Iowa, Missouri and Illinois. Wind chill warnings were posted for parts of Minnesota, warning of of wind chills as low as 45 below zero. Still, the picture was much calmer than over the weekend, when storms left at least 10 people dead. The tornado was one of two rated at EF2 to hit the state on Saturday. New York City set a record high Sunday at 71 degrees, National Weather Service meteorologist Ashley Sears said. The previous record, set in 1949 and matched in 1998, was 63. Rain was finally tapering off in Georgia, South Carolina and states in the Mid-Atlantic. A wave of cold temperatures will take its place Tuesday. The storms left some Michigan residents dealing with no electricity. CNN's Sean Morris, Adam Shivers, Todd Borek, Jareen Imam, Leslie Holland and Janet DiGiacomo contributed to this report.