http://reliefweb.int/sites/reliefweb.int/files/resources/CF4243D63D802AF9852578310077C30E-CW-2011-000018-MEX_0802.pdf] In Chihuahua City, the temperature dropped to -1.0 Farad  in Ciudad Juárez, which lies just across the border from El Paso, Texas, in the Mexican state of Chihuahua, a regional state of emergency was declared Tuesday evening, just ahead of the cold weather system, with Mexican authorities urging citizens to stay indoors.