CHARM, Cosmic High Altitude Radiation Monitor, is an observatory whose target is the study of cosmic rays. This is actually under construction stage, it consists of an array of Water Cherenkov Detectors (WCD) located in Puebla México, at 18.591N and 97.1876W, 4300 meters over sea level. Each WCD container inner walls is covered inside with a high UV reflective material called Tyvek, and it is filled with 12000 liters of pure water. The WCD has a sensitive area of 10 m², and the Photomultiplier inside (PMT) is an EMI 9530A (PMT), which has the acquisition electronic associated too. The observatory is designed to study high-energy cosmic rays in the range 1 PeV – 100 PeV. This work presents the actual status, the temporal structure signals (peak amplitude and integrated charge) and the stability of the Water Cherenkov Detectors. This study is performed using secondary particles from the background.