This is the 5th most frequent Italian word.
è
"È" means "is" (third person singular of the verb "essere," to be).
Here, 'è' links the noun 'Il clima' (The weather) with its descriptive characteristic 'piacevole' (pleasant), emphasizing a description.
Il clima è piacevole oggi.
The weather is pleasant today.
In this instance, 'è' is part of the compound past tense, accompanied by 'stato' (been), to express a completed event in the third person singular.
È stato un giorno fantastico.
It was a fantastic day.
In this sentence, 'è' functions as the third person singular form of the verb 'essere' (to be), indicating a current state or condition.