Local: Mass GIS | City of Boston | Metro Boston Data Common
U.S.: US Federal Government | USGS National Map Viewer | USGS National Map Services | Building Footprints | Daily P.M. 2.5 Air Pollution Data back to 2017 | First Street Foundation Tract Level Climate Risk
Global:
- Daymet V4 Climate and Daily Weather data
- Earthblox projected climate, land cover, and other nature scenarios (not free)
- Free GIS Data Sources
- Facebook Data for Good
- HADEX Land Surface Cimate Extremes
- iNaturalist contains crowdsourced observations of plants and animal species, available for download with free subscription.
- geoBoundaries country boundaries through time.
- Global Administrative Data (GADM) downloadable by country.
- Global Open Data for Agriculture and Nutrition
- Humanitarian Data Exchange
- The International Monitoring System includes seismic, hydroacoustic, infrasound and radionuclide data compiled on global scale.
- US Geological Survey
- Wikipedia GIS Data Resources
See also some curated lists of GIS data at these websites:
UPENN Library Guide to GIS Data