A climatic series (1941 to 1994) from a Mediterranean locality of NE S
pain was used to calculate two wildfire hazard indices based on daily
meteorological data. Both fire hazard indices increased over this peri
od, as a consequence of increasing mean daily maximum temperature and
decreasing minimum daily relative humidity. These trends were observed
in both mean values of the indices and in the number of very high ris
k days. Annual data on the number of wildfires and burned area also sh
ow an increase from 1968 to 1994, and are significantly correlated wit
h both fire hazard indices. Although other non-meteorological causes (
e.g., human activities, fuel accumulation) have likely contributed to
the observed increase of wildfires, an effect of climatic warming on w
ildfire occurrence is supported by this relationship.