By the early 1960s, the Meteorological Office had become respected around the world for its scientific and technological capabilities and the progress it had made towards realizing Richardson's dream of forecasting the weather by mathematical methodology. It had also long been a leading member of the international meteorological community. And yet, an international issue remained unresolved. The universal use of the metric system in meteorology had been opposed by the Office's Director at Leipzig in 1872, and the matter had continued to simmer. A partial introduction of the system in the Office had come just before the Great War, when there had been a change from inches to millimetres for measuring rainfall and inches to millibars for recording barometric pressure (see Chapter 8), but the Office and the British public had continued to use the Fahrenheit scale of temperature.

Fahrenheit or Celsius

A move to clear up the matter came in 1953, when the Executive Committee of WMO decided that degrees Celsius should be used for coding temperatures in all upper-air reports, and another move came in 1955, when the Second WMO Congress passed a resolution that the metric system be adopted for all international exchanges of meteorological information. The Third WMO Congress, in 1959, resolved that meteorological services which had still not adopted the metric system fully should do so, at least in coded messages for international exchanges, at some time in the period 1959 to 1963.