Of weather, seasons, etc.: not rough or stormy, not harsh or severe; calm, fine; moderately (esp. unseasonably) warm. Of a climate: temperate.

Of weather, a season, a day, etc. Free from storms or rough winds, or from cold or chill; calm, mild, balmy.

Of a season of the year: characterized by abundance of greenery, foliage, etc. Of a winter, Christmas, etc.: mild, without frost or snow.

Of the weather, wind, climate, etc.: not stormy, violent, or severe; mild. Cf. gentle breeze n. gentle gale n.

With reference to climatic conditions: favourable or conducive to growth or health; pleasantly warm or temperate. Formerly also with to. Also in…

Of weather or climate: Mild, gentle; opposed to inclement. rare.

Of wind, air, weather, etc. (combining senses 3 4): Deliciously mild, fragrant, and soothing.

Mellow; soft and insipid; (of weather) mild, humid. Also (in extended use): pleasant, agreeable.