NOAA Weather Radio is a service of the National Oceanic and Atmospheric Administration (NOAA) of the U.S. Department of Commerce. The "Voice of the National Weather Service", it provides continuous broadcasts of the latest weather information directly from the National Weather Service offices. Taped weather messages are repeated every four-to-six minutes and are routinely revised every one-to-three hours, or more frequently if needed. Most of the stations operate 24 hours daily.
The broadcasts are tailored to weather information needs of people within the receiving areas. For example, stations along the sea coasts and Great Lakes provide specialized weather information for boaters, fishermen, and others engaged in marine activities; as well as general weather information. During severe weather, National Weather Service forecasters can interrupt the routine weather broadcasts and substitute special warning messages. The forecasters can also activate specially-designed warning receivers. Such receivers either sound an alarm indicating that an emergency exists, alerting the listener to turn the receiver up to an audible volume; or, when operated in a muted mode, are automatically turned on so that the warning message is heard. "Warning Alarm" receivers are especially valuable for schools, hospitals, public safety agencies and news media offices.
Under a January 1975, WHite House policy statement, NOAA Weather Radio was designated the sole Government-operated radio system to provide direct warnings into private homes for both natural disasters and nuclear attack. This capability was to supplement warnings by sirens and by commercial radio and TV.
NOAA Weather Radio broadcasts are made on one of seven high-band FM frequencies ranging from 162.40 to 162.55 megahertz (MHz). These frequencies are not found on the average home radio now in use. However, a number of radio manufacturers offer special weather radios to operate these frequencies; with or without the emergency warning alarm. Also, there are now many radios on the market which offer the so-called "weather band" as an added feature.
NOAA Weather Radio broadcasts can usually be heard as far as 40 +- miles from the antenna site. The effective range depends on many factors; particularly the height of the broadcasting antenna, terrain, quality of the receiver and type of receiving antenna. As a general rule, listeners close to or perhaps beyond the 40 mile range should have a good quality receiver and an outside antenna mounted as high up as possible.
The National Weather Service operates about 372 stations. Approximately 90 percent of the nation's population is within listening range of a NOAA Weather Radio broadcast.