Understanding the nature and magnitude of the regional climatic variations is a key factor for the development of adaptation and mitigation policies. Because of this, the present paper analyzes the minimum and maximum temperature and precipitation records made by meteorological stations located at the State of Mexico between 1978 and 2000. To do so, we evaluate the means and coefficients of the variation of temperature and precipitation records in 92 stations located in the State of Mexico. We look for linear trends of behavior within these series. On each meteorological station, we calculated the coefficient of variation for all their registrations to find out which of them had the most variability. We cartographically represent the same variability in order to evaluate its spatial... distribution and search for spatial relationships. We found a statistically robust pattern of increasing variability on the records of temperature of maximum temperature for January, April and May and a minimum temperature for May, June and September; and a possible relation of the station with the most variability of maximum temperature and the presence of deforestation fronts.