Wildfires are great threat to nature and humans. Predicting fire occurrence, early fire detection and intervention can significantly diminish hazardous consequences. Therefore, fire risk index is used to quantify probability of fire occurrence at certain time and place, in order to help fire managers to organize fire protection in a better way. In this paper we have performed statistical analysis of past fires detected by satellites in respect to various parameters. We have taken into account meteorological, topological and anthropological parameters and study their influence on fire occurrence. Based on this study we proposed an improved method for calculating a site-specific fire risk index (SWRI), especially tuned for the Adriatic region.