The conversion
31°F = −0.56°C
°C = (°F − 32) × 5/9, so (31 − 32) × 5/9 = −0.56.
As an outdoor air temperature, 31 °F sits in the freezing band. The other scale is on the dial beside it in the app, so a reading like this needs no conversion at all.
Convert something else
68°F
The range either side
Neighbouring values, for when the number you actually wanted was a degree or two away.
| Fahrenheit | Celsius |
|---|---|
| 26 °F | −3.33 °C |
| 27 °F | −2.78 °C |
| 28 °F | −2.22 °C |
| 29 °F | −1.67 °C |
| 30 °F | −1.11 °C |
| 31 °F | −0.56 °C |
| 32 °F | 0 °C |
| 33 °F | 0.56 °C |
| 34 °F | 1.11 °C |
| 35 °F | 1.67 °C |
| 36 °F | 2.22 °C |
The other direction
−0.56 °C converts back to 31 °F, which is the same relationship read the other way. Going from Celsius to Fahrenheit, multiply by 9/5 first and then add 32. Adding first is the usual mistake.
The full converter handles any value, in either direction, including kelvin, and shows the formula as it works.