Jeff Masters, a doctoral candidate in meteorology at the University of Michigan working under the direction of Professor Perry Samson, wrote a menu-based Telnet interface in 1991 that displayed real-time weather information around the world.

The name is a reference to the 1960s radical left-wing militant organization the Weather Underground, which also originated at the University of Michigan. The company is based in San Francisco, California and was founded in 1995 as an offshoot of the University of Michigan internet weather database. Weather Underground is owned by The Weather Company, a subsidiary of IBM.

The site is available in many languages, and customers can access an ad-free version of the site with additional features for an annual fee. Its information comes from the National Weather Service (NWS), and over 250,000 personal weather stations (PWS). Weather Underground provides weather reports for most major cities around the world on its Web site, as well as local weather reports for newspapers and third-party sites.

Weather Underground is a commercial weather service providing real-time weather information over the Internet.

Weather forecast underground