The MODIS snow-cover products, developed from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite, provide global, high-resolution snow-cover information. These products are available through the National Snow and Ice Data Center (NSIDC) and are designed to improve upon existing operational snow-cover products. MODIS snow maps offer 500-m resolution and can distinguish snow from clouds, making them valuable for climate studies. The products include quality assurance (QA) information and are processed through a sequence of steps, including swath mapping, gridding, and composite tile production. A climate-modeling grid (CMG) product at 5-km resolution is also developed for use in climate models. The MODIS snow-mapping algorithm uses the normalized difference snow index (NDSI) calculated from MODIS bands 4 and 6 to identify snow-covered areas. The algorithm also considers reflectance in band 2 and adjusts for low reflectance values that may indicate dark targets. The algorithm is automated, ensuring consistent data for long-term climate studies. However, challenges remain, including cloud masking errors and spurious snow detection, particularly along coastlines and in areas with mixed pixels. A case study from March 6, 2000, compared MODIS snow maps with field measurements and other satellite data, revealing discrepancies in snow cover estimates. The MODIS snow map showed patchy snow cover in some areas, while field measurements indicated continuous snow cover. Another study on December 23, 2000, compared MODIS and Landsat-7 ETM+ data, showing that MODIS provided a more accurate representation of snow cover than the ETM+ data. Future enhancements include daily snow albedo and fractional snow cover products. The MODIS snow products are expected to improve the accuracy of snow-cover data for climate modeling and environmental monitoring. Despite challenges, MODIS snow maps are considered superior to other snow-cover products and are a key tool for monitoring global snow cover.The MODIS snow-cover products, developed from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite, provide global, high-resolution snow-cover information. These products are available through the National Snow and Ice Data Center (NSIDC) and are designed to improve upon existing operational snow-cover products. MODIS snow maps offer 500-m resolution and can distinguish snow from clouds, making them valuable for climate studies. The products include quality assurance (QA) information and are processed through a sequence of steps, including swath mapping, gridding, and composite tile production. A climate-modeling grid (CMG) product at 5-km resolution is also developed for use in climate models. The MODIS snow-mapping algorithm uses the normalized difference snow index (NDSI) calculated from MODIS bands 4 and 6 to identify snow-covered areas. The algorithm also considers reflectance in band 2 and adjusts for low reflectance values that may indicate dark targets. The algorithm is automated, ensuring consistent data for long-term climate studies. However, challenges remain, including cloud masking errors and spurious snow detection, particularly along coastlines and in areas with mixed pixels. A case study from March 6, 2000, compared MODIS snow maps with field measurements and other satellite data, revealing discrepancies in snow cover estimates. The MODIS snow map showed patchy snow cover in some areas, while field measurements indicated continuous snow cover. Another study on December 23, 2000, compared MODIS and Landsat-7 ETM+ data, showing that MODIS provided a more accurate representation of snow cover than the ETM+ data. Future enhancements include daily snow albedo and fractional snow cover products. The MODIS snow products are expected to improve the accuracy of snow-cover data for climate modeling and environmental monitoring. Despite challenges, MODIS snow maps are considered superior to other snow-cover products and are a key tool for monitoring global snow cover.