The Conjunctural and Meteorological Index (RCM) is calculated daily and results from the combination of two indices:
i) the “Fire Weather Index” (FWI), updated once a day by the IPMA;
ii) the “Rural Fire Hazard Index", which includes a structural component of decadal periodicity and a cyclical component of annual periodicity, which takes into account the burnt areas of the last three years, both under the responsibility of the Institute for Nature Conservation and Forests (ICNF).
The integration of the two indices is carried out by applying a weighting matrix. Agglutination by administrative unit (County and District) is carried out by weighting the highest class values, considering the threshold of 20% of the highest classes (80th percentile).
In 2022, the hazard index was updated on May 2nd and the weighting matrix on June 1st.