The Snow Meteorology and Phenology Classification (SnowMAP)

Snow is a vital water resource that regulates climate, supports ecosystems, and influences economies and transportation systems, making it essential to understand its physical properties and the seasonal timing of its presence (i.e., its phenology). Current approaches to classify snow globally separate snow’s meteorological controls from its phenology, limiting its decision-relevance. Here we provide SnowMAP, a global snow classification dataset that combines snow meteorological and phenology classes, mapped on a global 30 arc second (1/120° or ~1 km) grid. SnowMAP integrates meteorological factors such as snowfall, temperature, and wind (via Sturm and Liston 2021, https://doi.org/10.1175/JHM-D-21-0070.1) with seasonal dynamics like snow presence and melt timing (via Johnston et al., 2023, https://doi.org/10.1175/JHM-D-23-0047.1), providing a more complete view of global snow conditions. The resulting 18 snow classes reflect notable variations in meteorological conditions, snow depth, geography, and land cover. The meteorological metrics input into the classification are derived for the period from 1981 - 2019 (available at https://doi.org/10.5067/99FTCYYYLAQ0), and the snow cover metrics are derived using MODIS satellite observations collected during the period from 2000 - 2023 (available at https://doi.org/10.5067/9R1AM6NNZLTV). As a result, this record can be considered representative of the recent climatological period (1981-2023). Two files are included: (1) the 30 arc second degree georeferenced raster file (.tif) and (2) a legend table linking numeric ids in the raster file to each snow class and recommended color codes for visualization (.csv).