a place name, a municipality (also called Chalco Atenco in pre-Hispanic times); known today as Chalco de Díaz Covarrubias; and a large region in the southeast of the Valley of Mexico
Axcan domingo ynic cemilhuitl mani metztli de febrero de 1615. años. yhcuac cenca chicahuac ocehuetzico yn ayc yuh mochihuani nican Mexico. oc cenca ompa yn izquican chalco. mochi cecualloc. y nochiznopalli yn oquitocaca ytencopa Jues español topille yn quimocuitlahuiaya. ye otlatzicoca ye omozcaltiaya huel tlaltitech oquihuicac ynic oquipollo cetl huel ce semana yn chicahuac ocehuetz = Today, Sunday the first day of the month of February of the year 1615, was when there was a very severe freeze such as had never happened here in Mexico. Especially all over Chalco all the cochineal cactus froze that had been planted at the order of a Spanish judge, [a constable]. The [cactus] that they were cultivating had already taken root and started to grow, but the ice destroyed it and knocked it all the way down to the ground. For a whole week it froze severely (central Mexico, 1614–1615)