Fifty years ago on Thursday, the way we describe weather changed overnight when the Bureau of Meteorology (BOM) switched from Fahrenheit to Celsius.
The change was part of Australia's conversion to the metric system, overseen by the Metric Conversion Board.
And while the overall shift was a mammoth task, the transition was considered fairly seamless.
Retired meteorologist Mike Bergin, who was training with BOM at the time, said one of the biggest discussion points was whether or not to phase out Fahrenheit.
"And in the end, the decision was made that on the first day of September, we're going cold turkey, and it's the end of Fahrenheit, and we're starting with Celsius.
"So for many people, I'm sure that was a pretty dramatic sort of a decision."
Converting from Fahrenheit to Celsius was no small feat.
To do so, the BOM replaced 6,000 Fahrenheit thermometers and recovered the mercury from them.
They also had to convert 15 million historical temperature records from Fahrenheit to Celsius.
Catchy jingles replace the magic
And then there was the task of changing the language in everyday life.
"The one thing I can remember is that 100 degrees Fahrenheit was [thought as] some sort of magical, that's super hot, number," he said.
"Of course, it converts to a very awkward 37.78 degrees Celsius, so it loses its magic.
"But I think maybe 40C has become the 'oh, my goodness, it's really hot' point."
To help, the weather bureau coined a series of jingles to describe the feeling of a temperature in degrees Celsius.
These included the "frosty fives", "tingling tens", "temperate twenties", "thirsty thirties" and "flaming forties".
Miles to metric measurements
The switch from Fahrenheit to Celsius was the first phase of the BOM's change to metric.
At the same time, they abandoned the use of inches in air pressure.
Stage 2 of the conversion, in April 1973, changed wind speeds to kilometres per hour instead of miles per hour.
And the final stage, completed in 1974, saw rain heights, wave heights and snow depths changed to metres.
Mr Bergin said this change was more memorable.
"I know rainfall wasn't quite as smooth and nor was wind," he said.
"It's still the case today, if you travel rural and regional areas and speak to particularly older people, the language is still very much about inches.
"They'll tell you they're 50 kilometres from a certain town, but we had half an inch of rain last night."
Weather forecasts were not the only aspect of Australian life that changed to metric during that period.
Between 1970 and 1980 road speeds, dress sizes, scales, recipes and medical prescriptions were also converted, among others.
Despite the potential for disruption to normal life, the change was surprisingly trouble-free in both private and commercial spheres, according to a 1982 report by the federal government.
The report described the process of metrication as a "most significant event in Australia's integration with the modernising world", set in motion following the change to decimal currency in 1966.
A Senate committee determined the move to metric to be both desirable and practical — simpler, more efficient and more widely used around the world.
In 2022, just a handful of countries still use the Fahrenheit scale.
