TWN is owned by a Canadian company, Pelmorex, which is itself principally owned by Pierre L. Morrissette in partnership with the similar American service, The Weather Channel (now controlled by NBC Universal).

Pelmorex employs its own meteorologists to make forecasts and graphical weather products. Pelmorex meteorologists use an in-house technology called Pelmorex Forecast Engine or PFE. Pelmorex also uses a localization technology known as PMX, a proprietary system that is able to deliver separate forecasts for over 1200 locations across Canada.

The Weather Network began on September 1, 1988 as WeatherNow, under the ownership of engineering firm Lavalin Inc., now known as SNC-Lavalin. In the early years, the station had been noted for the number of technical difficulties since TWN and MétéoMédia shared a single television signal—the two originally shared an analogue transponder on one of the Anik satellites, with computer-generated local forecasts airing on one while the video feed of a live forecaster or TV commercials aired on the other. The channel gained its present name on May 1, 1989. The two stations began to run separately starting in 1994, while both were still based in Montreal. Initially, a separate feed was set up for MétéoMédia subscribers in the Montreal area, while the shared satellite signal remained in other parts of the country.

Local forecasts were generated using the same systems owned by The Weather Channel in the U.S. called WeatherStar. TWN began using its own system called PMX in 1996, which is still in use today.

Pelmorex purchased The Weather Network from SNC-Lavalin in 1993, two years after the merger of SNC and Lavalin. The channel launched its web site in 1996.

On Saturday, May 2, 1998, The Weather Network started broadcasting nationally from its Mississauga studio (1 Robert Speck Parkway, Mississauga, Ontario) after relocating from Montreal. New presenters had arrived at this time, as the ones from Montreal had the option of losing their jobs and staying there or relocating (today, Chris St. Clair is the only presenter from Montreal remaining). These new presenters included Anwar Knight, Kim MacDonald, and Rory O'Shea. While many of the Montreal presenters initially relocated, including Sherrie Claridge, Lila Feng and Randy Renaud, most were gone from TWN within a year, and generally moved back to Montreal.

The Weather Network launched its redesigned web site in September 1999, promising users a more dynamic and integrated web experience. New content such as regularly updated severe weather warnings, a national weather map illustrating current conditions, course-specific golf forecasts, and ski resort conditions, as well as UV, air quality, and pollen forecasts were incorporated in the new web site.

Late 2001 marked the beginning of a period of gradual, but significant changes with The Weather Networks programming, starting with the launch of a 7-day and short term precipitation forecast during the Local Forecast. In 2002, The Weather Network introduced "Metacast Ultra", a weather presentation system that consisted of weather maps featuring more than 1200 local communities, commuter routes and regional highways, animated weather icons, and higher resolution weather graphics.

The Weather Network unveiled a redesigned website in 2003 that was faster, more localized, and easier to use. The re-designed site offered clients the opportunity to produce 'weather-triggered ads'. In addition, clients were able to localize their ads by tagging location-specific information onto a particular city or area.

On March 29, 2004, The Weather Network introduced a new 14-day trend outlook as part of the local cable weather package. It provided a two-week look at how the weather would trend compared to normal temperature values and weather conditions for that time of year.