Cuernavaca is located about 85 km. (50 miles) south of Mexico City on the M-95 freeway. It is known as "the city of eternal spring" because of its consistent 27 °C year-round weather. Cuernavaca is truly in the heart of Mexico, and is surrounded by some of the most beautiful and culturally rich regions of the country.
The city's name comes from Nahuatl Cuauhnāhuac "place near trees" (IPA: [kʷawˈnaːwak]), the name of the pre-Columbian altepetl at the location. The name was altered to Cuernavaca by influence of the Spanish words cuerno "horn" and vaca "cow". From Wiki.