Breakdown of Það er skýjað núna en það rignir ekki.
vera
to be
en
but
það
it / there (existential) / the one (n)
ekki
not
Questions & Answers about Það er skýjað núna en það rignir ekki.
Why do we use það twice in this sentence?
In Icelandic, just like in English, we need a "dummy subject" to talk about the weather because there isn't a specific person or thing doing the action. We use það (it) to fill that grammatical role in both halves of the sentence: það er skýjað (it is cloudy) and það rignir (it rains).
Why is er (is) used with skýjað but not with rignir?
This is because skýjað (cloudy) is an adjective, so it needs the verb er (is) to make sense: "it is cloudy". However, rignir is an action verb meaning "rains". Just like we say "it rains" rather than "it is rains" in English, Icelandic says það rignir.
Why does the word skýjað end in -að?
Because the dummy subject það is a neuter pronoun, any adjectives describing the weather must be in the neuter singular form to match it. Skýjað is the neuter form of the adjective for "cloudy".