This is the 33rd most frequent French word.
était
"Was" (imperfect tense of "être" - to be).
Here, 'était' is used as the imparfait tense conjugation of the verb 'être' (to be) to describe the state of the weather in the past.
Le temps était magnifique hier.
The weather was wonderful yesterday.
In this example, 'était' denotes a continuous state in the past, being part of indirect speech.
Je pensais qu'il était déjà parti.
I thought he had already left.
'Était' here represents the past tense to describe a state or situation in reported speech.