This repository contains two complementary NetCDF datasets that support the analyses presented in our arXiv preprint:https://arxiv.org/abs/2503.01818 They provide global fire danger masks at a 1° spatial resolution, specifically tailored to wildfire danger assessments based on the Fire Weather Index (FWI). File 1: Mask of Infrequent Fires (1° Resolution) Contents: This file contains a spatial mask identifying regions with infrequent fire activity. Grid cells are marked based on criteria defined in the study (e.g., high proportions of bare areas, water, snow/ice, or sparse vegetation), thereby excluding areas unlikely to experience regular burning. Purpose: It serves as a baseline dataset to delineate areas where extreme fire weather events are less frequent, ensuring that subsequent analyses focus on regions of active fire dynamics. File 2: Mask with Trend Inconsistencies (1° Resolution) Contents: Building on the first file, this dataset incorporates additional masking to highlight regions where the trends in FWI—calculated using daily approximations—are not preserved when compared to the baseline noon-specific FWI (i.e., using the C1 combination as detailed in the preprint). Purpose: This file is particularly useful for identifying areas where daily meteorological approximations may introduce significant biases in the projected trends of extreme fire weather. Researchers can use this mask to better interpret the reliability of fire danger projections and to refine methodological approaches in climate change studies.