🌡️ Common Temperature Reference Table

Condition	°F	°C	K
Absolute Zero	−459.67	−273.15	0
Coldest recorded Earth surface (Antarctica, 2010)	−135.8	−93.2	180.0
Extreme Cold (Siberian winter)	−58	−50	223.15
Freezing point of water (ice melts)	32	0	273.15
Cold winter day	32 - 41	0 - 5	273 - 278
Cool autumn day	50 - 59	10 - 15	283 - 288
Mild / pleasant day	68 - 72	20 - 22	293 - 295
Typical room temperature	68 - 72	20 - 22	293 - 295
Human body temperature (normal)	98.6	37.0	310.15
Hot summer day	86 - 95	30 - 35	303 - 308
Heat wave / extreme heat	104	40	313.15
Boiling point of water (sea level)	212	100	373.15
Surface of the Sun	9,941	5,505	5,778

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📖 Understanding Temperature Scales

Why Does the United States Use Fahrenheit?

The United States, along with a few other territories (Bahamas, Belize, the Cayman Islands, and Palau), uses the Fahrenheit scale as its primary temperature standard. This dates back to the 18th century, when Fahrenheit was the leading scale worldwide. While most of the world adopted the metric system (and thus Celsius) during the 19th and 20th centuries, the U.S. never made a formal switch. Resistance to change, the cost of converting infrastructure (weather reports, thermostats, industrial processes), and cultural familiarity have kept Fahrenheit in everyday American life. Interestingly, the U.S. scientific and medical communities use Celsius (and Kelvin) for research, but Fahrenheit remains the default for weather, cooking, and household use.

The History of Temperature Scales

Fahrenheit (°F), Invented by Daniel Gabriel Fahrenheit in 1724. He set 0°F as the temperature of a brine solution (ice, water, and ammonium chloride) and 96°F as human body temperature (later recalibrated to 98.6°F). The scale was later refined so water freezes at 32°F and boils at 212°F, exactly 180 degrees apart.
Celsius (°C), Developed by Anders Celsius in 1742. Originally Celsius set 0° as the boiling point and 100° as the freezing point; the scale was inverted after his death. Today 0°C is the freezing point of water and 100°C is the boiling point at sea level, 100 degrees apart, making it a decimal-friendly scale that aligns with the metric system.
Kelvin (K).

The Conversion Formula Explained

The relationship between Fahrenheit and Celsius is linear. Here's how the formulas work:

Converting Fahrenheit to Celsius

To go from °F to °C, subtract 32 (to align the freezing points at 0°C) and then multiply by 5/9 (because 180 Fahrenheit degrees span the same range as 100 Celsius degrees).

°C = (°F − 32) × 5/9

Converting Celsius to Fahrenheit

To reverse the process, multiply the Celsius value by 9/5 (to expand from 100 Celsius degrees to 180 Fahrenheit degrees) and add 32 to align the scales.

°F = (°C × 9/5) + 32

Converting to / from Kelvin

Since Kelvin and Celsius share the same step size, converting between them is a simple addition or subtraction:

K = °C + 273.15 | °C = K − 273.15

Combined with the Fahrenheit formulas above, you can convert any temperature between all three scales.

Key Differences at a Glance

Scale size: One Fahrenheit degree is 5/9 the size of one Celsius degree. This means Fahrenheit provides more granularity without decimals for everyday weather.
Freezing point::
Boiling point::
Absolute zero::
Interesting overlap: At −40°, both Fahrenheit and Celsius read the same value (−40°F = −40°C).