In Tajikistan in the season of winter and the beginning of spring fog appears mostly in the valleys.
Туман дар вақти хунук будани сатҳи Замин ба вуҷуд меояд.
Fog appears when the surface of the earth is cold.
Пайдо шудан and ба вуҷуд омадан are synonyms.
To see more weather words from Word a Day click on the weather tag on the side of this page.
You can also learn weather words at Memrise – Tajik: Weather. (You have to sign up to use Memrise, but it is free.)