**4.1. Climatic data**

As it was mentioned, the climate that predominates in the region is warm humid and warm sub-humid, with an average maximum temperature of 36°C during the months of May and June and average minimum temperature of 18°C during January. However, in some occasions during August, the so-called *dog days* is presented, which is the year period where heat

**Figure 2.** Distribution of head of precipitation recorded from August 2013 to October 2014 in the Modesto Ángel station and the Automatic Weather Station (EMA)-CONANP station at the north and south of the study of the CBR, respectively.

is severe and drought is taking place. According to [30], the rainy season occurs during the middle of summer until autumn, although it was observed in **Figure 2** that occurs from July to February. During the winter, the tropical storms have influence on the generation of precipitations and also they cause a decrease of the temperature until reaching 10°C [30].

**Figure 2** shows the rainfall distribution in the study area. Although the north area seems more affected by the winter rainfall, there is more rain in the south part of the CBR. Besides, in the dry season from April to July, there was some rainfall at the north area. This variability favoured the presence of humidity maintaining the diversity of vegetation species in both areas. The archaeological zone is considered at the south.
