The United States uses Fahrenheit primarily due to historical inertia and the British colonial legacy. The scale was developed by Daniel Gabriel Fahrenheit in the early 18th century and gained prominence when he was inducted into the British Royal Society in 1724; as the British Empire expanded, it exported the Fahrenheit system to its colonies, including America.

While the rest of the world adopted Celsius as part of the metric system in the 20th century, the U.S. resisted conversion. Although Congress passed the Metric Conversion Act in 1975, it was voluntary rather than mandatory. Public resistance to learning new systems for weather and cooking, combined with industrial pushback, led to the dismantling of the Metric Board in 1982, cementing Fahrenheit as the standard for everyday use in the U.S., Cayman Islands, and a few other nations.

Many Americans also prefer Fahrenheit for practical daily use because it offers finer resolution for ambient temperatures. A one-degree change in Fahrenheit is smaller than in Celsius, allowing for more precise distinctions in weather without using decimals. Additionally, the scale’s range (0°F to 100°F) roughly corresponds to typical outdoor temperatures humans experience, making it intuitive for describing cold and hot weather