The conversion

37°F = 2.78°C

°C = (°F − 32) × 5/9, so (37 − 32) × 5/9 = 2.78.

As an outdoor air temperature, 37 °F sits in the cold 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 to Celsius either side of 37 °F.
FahrenheitCelsius
32 °F0 °C
33 °F0.56 °C
34 °F1.11 °C
35 °F1.67 °C
36 °F2.22 °C
37 °F2.78 °C
38 °F3.33 °C
39 °F3.89 °C
40 °F4.44 °C
41 °F5 °C
42 °F5.56 °C

The other direction

2.78 °C converts back to 37 °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.