<P> Metrication in Canada began in 1970 and while Canada has converted to the metric system for many purposes, there is still significant use of non-metric units and standards in many sectors of the Canadian economy . This is mainly due to historical ties with the United Kingdom (before metrication), the traditional use of the imperial system of measurement in Canada, proximity to the United States, and to public opposition to metrication during the transition period . </P> <P> Until the 1970s, Canada traditionally used the Imperial measurement system, labelled as "Canadian units of measurements" under Schedule II, Section 4 of the Weights and Measures Act (R.S., 1985, c . W - 6). These units have the same name and, with the exception of capacity measures such as the gallon, the same values as US customary units . For example, before metrication in Canada, gasoline was sold by the imperial gallon (about 4.55 litres). In cross-border transactions, it was often unclear whether values quoted in gallons, etc. were referring to the US values (3.79 litres) or the imperial values of these units . That a higher price was being charged did not always resolve the matter . </P> <P> The Liberal federal government of Pierre Trudeau first began implementing metrication in Canada in 1970 with a government agency dedicated to implementing the project, the Metric Commission, being established in 1971 . By the mid-1970s, metric product labelling was introduced . In 1972, the provinces agreed to make all road signs metric by 1977 . There was some resistance to metrication, especially as the sectors of the economy where the federal Weights and Measures Act required metric to be used grew in number . The metrication of gasoline and diesel fuel sales in 1979 prompted 37 Progressive Conservative Members of Parliament to open a "freedom to measure" gas station in Carleton Place, Ontario, selling gas in both imperial gallons and litres . The city of Peterborough, Ontario, was a noted hotbed of opposition to metrication, having been one of the government's three test centres for the metrication process . Bill Domm, a Member of Parliament representing the riding of Peterborough, was one of the country's most outspoken opponents of metrication . During this period, a few government employees lost their jobs for their opposition to metrication . Neil Fraser, an official with Revenue Canada who publicly opposed mandatory metric conversion, was dismissed for "conduct unacceptable for a public servant ." </P> <P> Since 1976, the law requires that all prepackaged food products must declare their mass or their volume in metric units, though Canadian imperial units are still legally permitted on packaging . Milk has been thoroughly metric since 1980 . In April 1975, Fahrenheit temperatures were replaced by Celsius . In September 1975, rainfall was first measured in millimetres and snow in centimetres . Since April 1976, wind speed, visibility, and barometric pressure have been in metric units, with the pressure in kilopascals instead of the hectopascals (millibars) used in most of the rest of the world . In September 1977, every speed - limit sign in the country was changed from miles per hour to kilometres per hour . </P>

When did canada switch from gallons to litres