This is the 3613th most frequent German word.
nas
The word "nas" does not exist in German. You may mean "Nase," which means "nose" in English.
In this sentence, 'nass' is used as a descriptive adjective to describe the condition of the street after rain.
Die Straße ist nass nach dem Regen.
The street is wet after the rain.
Here, 'nasse' is the declined form of the adjective 'nass' in conjunction with the plural noun 'Hände'.
Er hat nasse Hände, weil er gerade abgewaschen hat.
He has wet hands because he just washed dishes.
In this instance, 'nasse' is modifying the noun 'Wetter' and is declined appropriately for the context.