From the National Weather Service:

Special Weather Statement

Special Weather Statement
National Weather Service Buffalo NY
100 PM EST Thu Jan 10 2019

NYZ001>008-010>014-019>021-085-110600-
Niagara-Orleans-Monroe-Wayne-Northern Cayuga-Oswego-Jefferson-
Lewis-Northern Erie-Genesee-Wyoming-Livingston-Ontario-Chautauqua-
Cattaraugus-Allegany-Southern Erie-
Including the cities of Niagara Falls, Medina, Rochester, Newark,
Fair Haven, Oswego, Watertown, Lowville, Buffalo, Batavia,
Warsaw, Geneseo, Canandaigua, Jamestown, Olean, Wellsville,
Orchard Park, and Springville
100 PM EST Thu Jan 10 2019

...BITTERLY COLD WIND CHILLS EXPECTED TONIGHT INTO FRIDAY MORNING...

The combination of cold temperatures and persistent wind will make
tonight feel colder than it has been for quite some time. Wind
chills will drop below zero across most of Western New York, with
wind chill values as low as 25 below zero east of Lake Ontario.
The coldest conditions will be late tonight and early Friday
morning.

Frostbite and hypothermia can occur if precautions are not taken.
Make sure to dress properly if you are planning to be outdoors
during this time.