-21.5 Fahrenheit to Celsius
-21.5 degrees Fahrenheit equals
-29.72°C
-29.72 degrees Celsius
-21.5°F is -29.72°C, well below the point where water freezes. Roads ice over here, and this is where winter forecasts in northern climates spend most of the season. For reference, water freezes at 0°C, or 32°F.
How to convert -21.5°F to °C
Formula
°C = (°F − 32) × 5/9
Substituting -21.5°F
- -21.5 − 32 = -53.5
- -53.5 × 5/9 = -29.72
Fahrenheit places the freezing point of water at 32 rather than 0, so that offset comes off first. What remains is then scaled by 5/9, because a Celsius degree covers 1.8 times as much temperature change as a Fahrenheit degree.
How -21.5°F compares
| Reference point | Temperature | Difference |
|---|---|---|
| Freezing point of water | 0°C / 32°F | 29.7°C (53.5°F) colder |
| Room temperature | 21°C / 69.8°F | 50.7°C (91.3°F) colder |
| Body temperature | 37°C / 98.6°F | 66.7°C (120.1°F) colder |
| Boiling point of water | 100°C / 212°F | 129.7°C (233.5°F) colder |