NASA’s publicly available metadata repository, hosting diverse datasets related to science, including biological, physical, earth, and planetary science, heliophysics, astrophysics, space exploration, aeronautics, and more.

The Particle Data Group (PDG) is an international collaboration that provides a comprehensive summary of Particle Physics and related areas of Cosmology: the Review of Particle Physics.

NASA's collection astrophysics data centers. It also includes the Astrophysics Scientific Information Management Policy.

This NIST database consists of evaluated data for use in total-energy calculations of electronic structure by density-functional theory. It contains total energies and orbital energy eigenvalues for all atoms from hydrogen to uranium, with micro-Hartree uncertainty in the total energy; as computed in the local-density approximation (LDA), the local-spin-density approximation (LSD), the relativistic local-density approximation (RLDA), and scalar-relativistic local-density approximation (ScRLDA).

The Durham High-Energy Physics Database (HEPData) has been built up over the past four decades as a unique open-access repository for scattering data from experimental particle physics. It currently comprises the data points from plots and tables related to several thousand publications including those from the Large Hadron Collider (LHC).

The CERN Open Data portal is the access point to a growing range of data produced through the research performed at CERN. It disseminates the preserved output from various research activities and includes accompanying software and documentation needed to understand and analyse the data.

Includes current and forecast air quality maps and data for more than 500 cities across the U.S, air quality data for Canada and Mexico, and current fire conditions including fire locations, smoke plumes, and air quality data.

A network of over 60 data repositories operated by research centers, universities, non-profit organizations, citizen science initiatives, government and non-government organizations. The repositories share data and infrastructure with DataONE which then facilitates user access to data and interoperability between members.

The EPA's environmental data. Includes data sets on air, land, water, waste, toxics, radiation, facilities, compliance, and more.

NSF's domain-specific lists of repositories, such as the Arctic Data Center.

This platform enables researchers to use spatial data pulled from over 400 layers on nature, climate change, and sustainable development.

The portal allows users to search information by thematic area, donor, geographic location, project status (ongoing/completed), or obtain an overview of project funding.

National Climatic Data Center's archive of global historical weather and climate data. Also includes station history information.

The IRI Data Library is a powerful and freely accessible online data repository and analysis tool that allows a user to view, analyze, and download hundreds of terabytes of climate-related data through a standard web browser.

U.S. Geological Survey Water Resources Mission Area for data, maps and reports.

An international data center under the World Meteorological Organization (WMO). Acquisition and management of historical river discharge data and associated metadata.

A curated collection of marine geophysical data products and data related to understanding the formation and evolution of the seafloor and sub-seafloor.