Temporal and spatial distribution patterns of detected fire affected pixels within the Experiment for Regional Sources and Sinks of Oxidants (EXPRESSO) window from 1994 to 1997 were analyzed, and key parameters for describing the fire regime for each season were determined. The parameters were three temporal parameters and five spatial parameters. The spatial parameters were shown to be highly correlated, while the temporal parameters only show low correlation coefficients. The spatial parameters were transformed into the first principal component which was used for subsequent analyses. The temporal parameters were used in a decision tree classification to classify fire regimes, based on the onset of the season, the steepness of a hypothetical logistical curve, and the length of the fire season. This classification resulted in three generic fire regime types; rapid increase regime, late fire regime, and prolonged fire regime. By a combination of temporal generic fire regime types with the first principal component, representing most of the variance in the spatial parameters, the fire regimes of the EXPRESSO window were classified into 12 different regimes. These fire regimes were found to be correlated to the general vegetation types, and it was found that, even though interannual fluctuations in the fire regime existed, the major part of the EXPRESSO window is affected by low and average intensity rapidly increasing fire regimes and that the late and prolonged fire regimes occur mainly in the southeastern parts of the EXPRESSO window. Furthermore, it is shown that the spatial extent of the fire regimes is controlled by vegetation zone characteristics. ¿ 1999 American Geophysical Union