Why two temperature scales exist
Fahrenheit was devised in the early 18th century by German physicist Daniel Gabriel Fahrenheit and predates Celsius. Later, the more intuitive Celsius scale, based on water's freezing and boiling points, was devised by Swedish astronomer Anders Celsius and adopted by most countries.
Why the US still uses Fahrenheit
Even as international adoption of the metric system has progressed, the United States remains one of the few countries that continues to use Fahrenheit and the customary (yard-pound) system in everyday life. Fahrenheit is still widely used in contexts like weather forecasts and cooking recipes.
Frequently Asked Questions
What should I do if a weather forecast abroad shows Fahrenheit?
The quick estimate (subtract 30 from the Fahrenheit number, then divide by 2) gives you a fast rough sense of the Celsius equivalent. For an exact figure, use the full conversion formula or a conversion app or search tool on your phone.
What if a recipe lists oven temperature in Fahrenheit?
Oven temperatures can be converted precisely using "Celsius = (Fahrenheit − 32) × 5/9." Making a small reference chart of commonly used temperatures in advance saves you from recalculating every time you cook.