All he had lov'd, and moulded into thought, From shape, and hue, and odour, and sweet sound, Lamented Adonais. Morning sought Her eastern watch-tower, and her hair unbound, Wet with the tears which should adorn the ground, Dimm'd the aëreal eyes that kindle day; Afar the melancholy thunder moan'd, Pale Ocean in unquiet slumber lay, And the wild Winds flew round, sobbing in their dismay.
Everything that Adonais loved was sad to see him go, even inanimate objects.
Even the morning wept for him, with "aëreal" eyes (eyes that look through the air). Giving human feelings to inanimate things is an example of Shelley's use of personification.
A few more personified mourners show up: the thunder, the ocean, and the winds. Man, this dead youth sure was a popular guy.