-40F = -40C | Equal Temperature Point

P2 / shareable fact

-40 is the only equal point

Fahrenheit and Celsius cross only once. That crossover happens at minus forty.

-40 °F

same

-40 °C

The two scales intersect at a single shared value.

Why it happens

The scales use different zero points and step sizes.

Celsius is anchored to water freezing and boiling, while Fahrenheit uses a different zero point and smaller degree steps. The math lines up only once.

Useful memory trick

Remember -40 for both.

If you ever need one temperature where the systems match perfectly, this is the one to keep in mind.