The Center for International Earth Science Information Network (CIESIN) is a center within the Earth Institute at Columbia University. CIESIN works at the intersection of the social, natural, and information sciences, and specializes in on-line data and information management, spatial data integration and training, and interdisciplinary research related to human interactions in the environment (source: website)
The NSIDC "supports research into our world's frozen realms: the snow, ice, glaciers, frozen ground, and climate interactions that make up Earth's cryosphere. NSIDC manages and distributes scientific data, creates tools for data access, supports data users, performs scientific research, and educates the public about the cryosphere." (source: website)
From the National Oceanic and Atmospheric Administration (NOAA)
NCEI puts a priority on interpreting and applying scientific understanding to our extensive array of climate datasets. Some of the products and output derived from this effort include extreme event and dynamically generated climate information. NCEI is the world’s largest provider of weather and climate data. Land-based, marine, model, radar, weather balloon, satellite, and paleoclimatic are just a few of the types of datasets available. (source: website)
From the U.S. Department of Commerce, National Oceanic and Atmospheric Administration, and the U.S. Department of Agriculture
"The WWCB provides a vital source of information on weather, climate and agricultural developments worldwide, along with detailed charts and tables of agrometeorological information that are appropriate for the season. The Bulletin is posted every Tuesday by 4:00 p.m. (ET). Posting will be delayed to the next business day when federal offices are closed."