The conversion

8°C = 46.4°F

°F = (°C × 9/5) + 32, so (8 × 9/5) + 32 = 46.4.

As an outdoor air temperature, 8 °C sits in the cool 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.

Celsius to Fahrenheit either side of 8 °C.
CelsiusFahrenheit
3 °C37.4 °F
4 °C39.2 °F
5 °C41 °F
6 °C42.8 °F
7 °C44.6 °F
8 °C46.4 °F
9 °C48.2 °F
10 °C50 °F
11 °C51.8 °F
12 °C53.6 °F
13 °C55.4 °F

The other direction

46.4 °F converts back to 8 °C, which is the same relationship read the other way. Going from Fahrenheit to Celsius, subtract 32 first and then multiply by 5/9 — doing it in the other order is the usual mistake and produces a plausible-looking wrong answer.

The full converter handles any value, in either direction, including kelvin, and shows the formula as it works.