This database is freely available to the general public via the Internet.

NCEI is the section of the National Oceanographic and Atmospheric Administration (NOAA) that preserves and provides climatic data to the public, business, industry, government, and researchers. It is the largest weather archive in the world housing information collected by Thomas Jefferson, as well as that collected by modern satellites. NCEI responds to worldwide inquiries about the climate. It acquires information from the National Weather Service, the military, the Federal Aviation Administration, the Coast Guard, and voluntary cooperative observers. Topics cover current events, products and services, free data, data access tools, most popular resources, links to regional climate centers, and data about global hazards.

NCEI maintains the following databases:

• Global Atmosphere Watch (GAW)
  https://community.wmo.int/en/activity-areas/gaw
  Analyzes data about the chemical composition and physical characteristics of the atmosphere to measure trends and effects on interactions with the oceans and the biosphere.
• Global Climate Observing System (GCOS)
  gcos.wmo.in/en/home
  Deals with satellite and in situ observations in the atmosphere, oceans, and land.
• Global Ocean Observing System (GOOS)
  goosocean.org
  Observes and analyzes the world's oceans.
• Global Terrestrial Observing System (GTOS)
  gssd.mit.edu/search-gssd/site/global-terrestrial-observing-system-gtos-52742-mon-07-23-2012-0859
  Helps researchers and policy makers manage global and regional environmental change by observing, modeling, and analyzing ecosystems that support sustainable development.

See also NCEI's Online Climate Data Directory at https://www.ncdc.noaa.gov/cdo-web/.

Federal law requires NOAA to recover its costs by charging for selected data. However, all information is gratis for users in the gov, edu, mil, and us domains. Free data is also available for K-12 education.

18th Century - present.

Select the Free Data link on the home page to view nearly 40 titles in pdf and/or html formats. 

NCDC - Image and Publications System
https://www.ncdc.noaa.gov/IPS/index.jsp
View current and historical local climatological data, hourly precipitation data, storm data, national summary data, and world monthly climatic statistics.