Of the weather: pleasant, clement; not wet or windy. Sometimes more strongly: bright, sunny. Cf. foul, adj. 9a.

Of weather, climate, a season, a day, etc.: pleasant, fine. Of a wind: favourable for sailing. Also figurative. Obsolete.

Of the weather: originally. Full of sunshine, bright, ‘fine’; serene, ‘fair’. Obsolete. (Cf. to clear up.)

Of the weather: favourable; clement. Now rare.

Of the weather, a day, etc.: bright, clear; free from rain or fog; (now often) pleasantly warm and sunny. Cf. fair, adj. 7a(a).

Characterized by the presence of a blue sky, as an indicator of pleasant weather. In extended use: cheerful, happy; optimistic.