The concept of fire regime refers to a variety of fire characteristics occurring at a given place and period of time. Understanding fire regimes is relevant to fire ecology and fire management because it provides a better understanding of effects of fire as well as the potential effects of different future scenarios. Recent changes in the traditional fire regimes linked to climate and socioeconomic transformations in European Mediterranean areas have influenced fire regimes and their effects on both ecosystems and people. This paper presents a methodology for characterising fire regimes based on historical fire statistics. The analysis includes three dimensions: density, seasonality and interannual variability. The raw records were pre-processed to eliminate errors, and a principal component analysis was performed to identify the primary factors involved in the variation. A cluster analysis was then used to define the fire regimes. Approximately 38% of the spatial cells examined were found to have significant fire activity, but in spite that fires are important in these areas, fire activity showed a high interannual variability. Four fire regimes in the Spanish peninsular territory were described in terms of the density and seasonality of fire activity.