There is fog but it is not thick, your vehicle has fog lights. Which lights must you switch on?

The front fog light is an OPTIONAL light used to improve road visibility in case of fog, snowfall, storm or dust cloud.

The rear fog light should ONLY be worn when weather or environmental conditions are particularly unfavorable, such as heavy fog, heavy rain, heavy snowfall, or dense clouds of dust or smoke.

Since in this case the fog is not thick, it is only necessary to switch on the front fog light.