The Weather Underground, Weather Network and Weather Warehouse websites provide historical weather information, including rainfall data, for cities in the United States and around the world. Weather Warehouse, for example, offers past weather data for some stations as far back as 1902.
The Weather Warehouse acts as the archival arm of the Weather Source, a private company that specializes in historical weather data, quality control, enhancement, probability and statistics metrics. It was founded in 2004 to provide weather data products to a range of clients.
The historical data from Weather Underground, Weather Warehouse and other websites rely on the information collected from a network of, as of 2015, over 18,000 National Weather Service stations. This government service is a division of the National Oceanic and Atmospheric Administration, in turn an operating unit of the U.S. Department of Commerce.
The National Weather Service, headquartered in Silver Spring, Maryland, has six regional offices throughout the United States. It employs 5,000 people in 9 national centers, support offices, 13 river forecast centers and 122 weather forecast offices. The National Weather Service issues 1.5 million forecasts and 50,000 warnings every year based on 76 billion observations. It is led, as of 2015, by the Director, Dr. Louis Uccellini, who also acts as the NOAA Assistant Administrator for Weather Services.