It's very foggy.

雾很大。

There's a heavy fog.

有浓雾。

It isn't foggy now.

现在没有雾了。

Winter brought the fogs.

冬天有雾。

The campus was surrounded in mist.

校园被蒙上了薄雾。

It's cold and foggy in London at this time of( the) year.

伦敦每年这个时候又冷又多雾。