A weather radio service is a broadcast service that airs weather reports. When the radio is on and tuned to the weather band, it airs both normal and emergency weather information. If the radio is off or tuned to another band, it automatically turns on and goes to the weather band for emergency weather information.
Weatheradio services may also broadcast non-weather related emergency information, such as in the event of a natural disaster, an AMBER alert or a terrorist attack. They generally broadcast in a preallocated VHF frequency range using FM. Usually a dedicated weather radio receiver or radio scanner is needed for listening, although in some locations a weatheradio broadcast may be retransmitted on a conventional AM or FM frequency (as well as HD Radio substations), some terrestrial television stations broadcasting in MTS stereo transmit weather radio on their second audio program (SAP) channel as well as on one of its digital subchannels (where news and weather are applicable), on local Public, educational, and government access (PEG) cable TV channels or during Emergency Alert System activations for tornado warnings primarily on cable systems.
Weather radios come with several features that make them very helpful in case of an emergency. Some models use crank power, in addition to mains electricity and batteries in case of a power outage. Some models have an embedded flashlight, and can double as a cellphone charger. Some also serve as a more general emergency radio.
Weather radios are widely sold in home electronics stores and even many supermarkets and drugstores in the United States and Canada. The price of a consumer model weather radio varies depending on the model and its extra features.
Most 21st century receivers are able to listen silently for weather alerts via the SAME protocol and then sound an alarm to warn the listener of the oncoming weather or event. Additionally many weather radio vendors also include a visual element such as colored warning LEDs or strobe lights which attach via an accessory port to give a warning to those who are hearing impaired.
| Frequency | Old name | New name |
|---|---|---|
| 162.4 MHz | WX 2 | WX 1 |
| 162.425 MHz | WX 4 | WX 2 |
| 162.45 MHz | WX 5 | WX 3 |
| 162.475 MHz | WX 3 | WX 4 |
| 162.5 MHz | WX 6 | WX 5 |
| 162.525 MHz | WX 7 | WX 6 |
| 162.55 MHz | WX 1 | WX 7 |
The United States, Canada and Bermuda operate their government weather radio stations on the same band.
Notable weatheradio services include:
The original numbering was from the order in which the frequencies were assigned, with 162.55 at first the only frequency, then 162.4 and 162.475 added later to prevent RF interference. The others mainly came into use in the 1990s in less-populated rural, areas and as fill-in broadcast translators relaying an existing station into remote or mountainous areas.
Canadian broadcasts are also transmitted on travelers' information stations on FM and AM, especially near national parks. Bermuda has only one station dedicated purely for weather, on 162.55 MHz from Hamilton, now operated by the Bermuda Weather Service. It has a second station, however, for marine conditions and forecasts, ZBR, at 162.400 MHz.
All stations transmit a 1050 Hz tone immediately before issuing a watch or warning, and this serves to activate the alert feature on many older radios. Except for Bermuda, all U.S. and later Canadian stations transmit WRSAME codes that allow more advanced receivers to only listen for certain warnings that carry a specific code for the local area, and often to alarm only for serious warnings (for example, a flash flood warning could be ignored by a person living on the top of a hill, while a tornado warning is an immediate emergency in all cases).
The weather radio band is reserved for governmental services. However, most AM and FM radio stations provide some sort of private weather forecasting, either through relaying public-domain National Weather Service forecasts, partnering with a meteorologist from a local television station, or affiliating with a commercial weather service company. Accuweather (through United Stations) and The Weather Channel (through Westwood One) both operate large national weather radio networks through AM and FM stations.