How does this "natural order" progress in lines 3 - 8 of Shakespeare's 18th sonnet?

REally Shakespeare is referring to the very natural passage of time,

Rough winds do shake the darling buds of May,

And summer's lease hath all too short a date:

Sometime too hot the eye of heaven shines,

And often is his gold complexion dimm'd;

And every fair from fair sometime declines,

Summer eventually ends "summer's lease hath all too short a date" and the "complexion" of the sun fades into the coolness of fall. Shakespeare extends this passage of time to his love but unlike the seasons, his lover's beauty is perennial.