The freezing cold air from the arctic has arrived after a heavy snowstorm hit the Northeast in January, bringing over a foot of snow and sleet. This led to dangerous conditions, as seen in a Chicago suburb where a 12-year-old girl tragically died when a snow fort she built collapsed on her. Her 9-year-old friend also suffered from hypothermia but was rescued and expected to recover. Temperatures dropped significantly, reaching single-digit Fahrenheit levels across New York City, Boston, and northern New England, causing the melting snow to freeze. Strong winds of up to 30-40 mph added to the dangerous conditions, creating potentially deadly wind chills. Chenard stated that the weather is extremely dangerous, with temperatures dropping to negative 20s in Minnesota and Wisconsin. Boston will be at 3 degrees Fahrenheit in the morning with wind chills of minus 12 or lower. New York City and DC will also experience similar temperatures, possibly reaching the teens later in the day, setting record or near-record cold temperatures. The National Weather Service has issued wind-chill advisories and warnings for over 10 states, ranging from North Dakota to East Coast cities. High temperatures for Monday are expected to be 17 Fahrenheit for New York City and 12 F for Boston. A large number of Americans had the day off on Monday, either due to the holiday or because they are part of the furloughed federal government workers affected by the longest shutdown in US history. This shutdown is a result of a disagreement over funding for President Trump's plan to build more barriers on the US-Mexico border. Flight delays, mainly in New York and New England, were reduced to over 7,500 on Monday from over 14,000 on Sunday, according to FlightAware.com. The weather on Tuesday will be slightly warmer, with temperatures in the Northeast reaching the low 20s Fahrenheit.