Weather Radio

Bill's  Radio Site

Last updated November 5, 2013

This page is written by Bill, using multiple sources, including official, and from personal experience.

This page is not intended to be an in-depth description of the Weatheradio system, or in any way a user's guide.  It is intended to be an introduction to the network and to the non-weather use of the system by scanner listeners.   I myself do on occasion listen to the content on Weatheradio but have never bothered with the alert function nor have I purchased a dedicated weather broadcast receiver.  If you are looking for information on how to use the broadcasts you are advised to go to the official websites indicated below, or to the various Wikipedia articles on the subject. 

Please note that this page is rarely updated and therefore when you read it there may have been additions to the network or changes in frequency.   For example in 2013 the transmitter at Nuttby Mountain (Truro) changed from 162.40 to 162.50 MHz, which is the first use of this frequency in the Maritimes.    It is anticipated in 2013 that the Souris transmitter on 162.40 will change to 162.525 in the future, and may have done so when you read this.     These changes are due to the fact that 162.40 was being utilized by several adjacent transmitters in the relatively small PEI and northern Nova Scotia area, something that likely was a problem in the regions lying midway between the transmitters.


Weatheradio or Weather Radio refers to the systems of civil VHF weather broadcasting transmitters in the United States and in Canada, and which may also be operating in other jurisdictions.    It does not refer to other types of weather broadcasts such as by marine coast stations.    

USA   (link to official site) (link to Wikipedia page)

Weather radio as defined above began in the United States when 162.550 MHz was set aside for broadcasts across the country but at some point not long after, the frequencies of 162.40 and 162.475 were added.     Later, with the proliferation of transmitters, the frequencies of 162.425, 162.450, 162.50 and 162.525 were inserted.    This band of frequencies was taken from the larger United States federal government band, which has a channel spacing (before narrow banding) of 25 kHz.

Due to the chronological implementation of these frequencies the most common designation of the frequencies is in the order that the frequencies are shown in the preceding paragraph, i.e. Wx1 is 162.550 and Wx7 is 162.525.      Some receiver manufacturers have on their own rationalized the designations so that they are in ascending frequency order with Wx1 being 162.40 and Wx7 being the original 162.550.    

Some have commented that it is unfortunate that the system was implemented in a band that requires a radio receiver separate from standard entertainment broadcast receivers.     Similarly it has been noted that with today's technology manufacturers of automobile radios could add reception of these channels to standard receivers and thereby vastly increase the utility of the system.

Despite the staggered introduction of the seven frequencies, all of them are in common use throughout the US.  In relatively isolated areas it is likely however that 162.550 remains the most common, as are the second two frequencies to a slightly lesser extent.    Due to the band being already a federal government-only part of the spectrum, there are no conflicts with other users.

In the United States the system is run by the National Weather Service, a unit of NOAA, the National Oceanic and Atmospheric Administration, which itself is part of the Department of Commerce.    Due to the fact that this system is now mandated to broadcast a variety of alerts other than those of a meteorological nature it is now called NOAA All Hazards Radio  or NOAA Weather Radio All Hazards.

Even if you are not interested in the weather broadcast content, these broadcasts are of interest to the scanner listener in two respects.  On one hand they can be the object of pursuit in dx'ing (unusual distant reception for enjoyment) or more simply can be used to gauge reception conditions in general.   For example, if I can hear weather radio transmitters in Maine from here in Halifax, then I will turn my attention to seeing what I can log in VHF radio in general or on the FM broadcast band.  There is more interest perhaps in listening to the American system, which is very extensive, because the transmitting stations are relatively localized and independent.     This means that adjacent stations are likely to be broadcasting different messages tailored to the local area which may be a county, a region or a metropolitan area.    Some of the broadcast will be the same but the order of presentation may differ, and the inclusion or exclusion of information for various localities will vary.    In addition, in the US the broadcasts will clearly indicate the point of origination of the broadcast and the call letters of the transmitter, and may also include the the transmitter site.

As is well known, the US system has for some time for the most part used synthetic voices that have evolved over time.    This evolution is well described in various on-line articles.   Canada also uses synthesized voices but different from the American ones.


CANADA  (link to official site) (link to Wikipedia page)   Bill's map for the Maritimes and adjacent Maine.  Please note that this map does not reflect changes made or anticipated in 2013 for Truro (Nuttby Mtn) and Souris PEI.

Weather radio in Canada is operated by the Meteorological Service of Canada (MSC), a division of Environment Canada.

Canada instituted the weather radio system after the United States and as is often the case, for practical reasons, adopted the same set of frequencies.   The complication in Canada however is that the 162 MHz portion of the VHF spectrum in Canada is not a federal government sub-band.    It is just another part of the land mobile band extending from the top of the VHF marine band at approximately 162 MHZ all the way to 174 MHz.    This means that the Canadian government superimposed the weather radio band of seven frequencies (with a spacing of 25 kHz) over top of the larger commercial band (with a spacing of 15 kHz).   Not only did this mean that there are incompatible frequency assignments, it also meant that there were other users already on the band.    This chart illustrates the frequency clash.   For the pink frequencies the clash is obvious as the frequencies fit both band plans.  For the others, there will be possible clashes such as a situation where an existing land mobile user is on 162.405 MHz, and therefore making weather radio frequency 162.40 unusable in that area.    One could say that Industry Canada and its predecessors could have forced the existing users to other frequencies but that simply has not happened.

162.39 Canadian Land Mobile Frequency
162.40 Superimposed Weather Radio Frequency
162.405 Canadian Land Mobile Frequency
162.42 Canadian Land Mobile Frequency
162.425 Superimposed Weather Radio Frequency
162.435 Canadian Land Mobile Frequency
162.45 Coinciding Canadian Land Mobile Frequency AND Superimposed Weather Radio Frequency
162.465 Canadian Land Mobile Frequency
162.475 Superimposed Weather Radio Frequency
162.48 Canadian Land Mobile Frequency
162.495 Canadian Land Mobile Frequency
162.50 Superimposed Weather Radio Frequency
162.51 Canadian Land Mobile Frequency
162.525 Coinciding Canadian Land Mobile Frequency AND Superimposed Weather Radio Frequency
162.54 Canadian Land Mobile Frequency
162.55 Superimposed Weather Radio Frequency
162.555 Canadian Land Mobile Frequency

Here in the Maritimes it is particularly relevant to note that there are "Pink" clashes.    Irving Industries uses 162.525 in south-western New Brunswick,  making it unusable for Weatheradio in the area (including nearby parts of the US)     In Nova Scotia, the Nova Scotia Power Corporation already uses 162.450 MHz throughout the province for data transmission, and therefore it is highly unlikely that this weather radio channel can be used anywhere in the province or nearby.    In a wider sense it can be readily seen in TAFL that across Canada there are quite a number of conflicting users so that Environment Canada does not have a free rein to use the 7 frequencies in to the same extent as the US NWS.    Canada uses 162.55 and 162.40 much more than the other frequencies.  One good result of this is that I, until recently, had no nearby transmitters on anything but 162.55 and 162.40 and therefore was able in good conditions to hear distant stations on the other frequencies, for dx'ing enjoyment.  I am able to dx 162.45 despite NS Power locally using the frequency because NS Power's transmissions are only periodic data bursts.

As noted above there is now a wide coverage transmitter at Nuttby Mountain on 162.50 MHz, so that frequency is now not usable for me to hear stations in Maine.

The Canadian weather radio system does in fact use other frequencies, outside of the normal weather radio channels.    In British Columbia and Ontario, and in one case in Nunavut, the weather radio service is broadcast in some cases on regular broadcast band frequencies, both AM and FM.    Examples are Revelstoke, BC on 1580 kHz and Algonquin Park, Ontario on 100.1 MHz.   Some or all of these "broadcast band" transmitters are operated by the CBC.

On the British Columbia coast there is a somewhat bizarre situation in which the weather band frequencies have been partially pre-empted by the Canadian Coast Guard and are used for continuous marine broadcasts (CMB) instead of Environment Canada broadcasts.   This appears to result from the CCG commencing broadcasts prior to the weather radio system being set up.     Elsewhere in Canada the CCG uses marine band channels such as Ch21B (161.65 MHz) and Ch83B (161.775 MHz) for its broadcasts but on the BC coast it uses both sets of frequencies (marine and weather).     An example of CCG usage of weather radio frequencies includes Victoria Coast Guard Radio's broadcast from Bowen Island on 162.475 MHz; however there are 17 other usages of 162.40, 162.475 and 162.55 MHz on the BC coast.   This of course means that if you turn on a dedicated weather radio, or service scan on your scanner, on the BC coast you are just as likely to hear the Coast Guard as you are to hear Weather Radio.     Of course it is true that amongst other things, the CCG broadcasts do include weather, but tailored to the mariner.  Just as a side note, most marine VHF radios used in North America do come equipped with the 7 weather radio channels in addition to the normal marine band frequencies, as they are in fact quite close in the spectrum.

A downside of the Canadian system relative to the US one, for scanner listeners, is that many or most of the Canadian transmitters are in groups of satellite stations that broadcast the same thing.  For example the Halifax and Shelburne transmitters are both on 162.55 and transmit the identical content.    There does not seem to be the phrases along the lines of "This is VGW34, the Weather Radio transmitter at Shelburne, Nova Scotia, broadcasting on 162.55 MHz and serving the south shore region."    You won't hear anything like that, at least not in this region!    Even when I listen from Halifax to the signal that I hear regularly on 162.40 I am really just guessing that it is the Truro transmitter.