First of all, the title might give information about the content of the poem: the poet might refer to the West Wind that could be considered an element of reflections for the poet.
The Ode is organized into five stanzas ending with a couplet, they also recall the tercets of Dante's "terza rima".
Reading the poem, in the first three stanzas the speaking voice describes the effects of the wind on the earth, the sky and the sea. In the second part of the Ode the poet refers to the hope of higher identification process conveied by the West Wind.
Going in depth, the West Wind acts as a driving force for change in the human and natural world. Shelley views winter as the last phase of life in the individual, the imagination, civilization and religion. Moreover the speaking voice observes the changing of the weather and its effects on the internal and external environment.
Shelley begins his poem by addressing the "Wild West Wind". He quickly introduces the theme of death and compares the dead leaves to "ghosts". The imagery of "Pestilence-stricken multitudes" makes the reader aware that the poem is addressing more than a pile of leaves. His claustrophobic mood becomes evident when he talks of the "wintry bed" and "The winged seeds, where they lie cold and low/ Each like a corpse within its grave, until/ Thine azure sister of the Spring shall blow".
The most important word is "seeds" because it shows that even in death, new life will grow out of the "grave."
Moreover the word "Spring" besides being a literary metaphor for rebirth also means to rise up.
At the end of the first stanza, the Wind is called "Destroyer and Preserver" to underline the double aspect of the energy of wind.
In the second stanza, the poem shows a shift of point of view. As a matter of fact the speaking voice looks at clouds which warns of an upcoming storm. The reader feels somewhat claustrophobic. The "closing night" feels as if it is surrounding the author as he writes and the reader as he or she reads. The "closing night" is used also to mean the final night. Shelley says how he cannot have a transcendence even in an open sky for even the sky is a "dome." The "sepulchre" is a tomb made out of rock and his imagination and the natural world will be locked and "Vaulted" tight. But in following lines the poet writes how this "sepulchre" will "burst". In that sense, "Vaulted" takes on the meaning of a great leap and even a spring. The poet wants the reader to visualize the "dome" as having a presence like a volcano. And when the "dome" does "burst," it will act as a "Destroyer and Preserver" and creator. The use of the words "Black rain and fire and hail..." also helps the reader prepare for the apocalyptic climax which Shelley intended.
In the third stanza Shelley talks of the "Mediterranean" and its "summer dreams". In the dream, the reader finds the sea laying "Beside a pumice isle in Baiae's bay/ And saw in sleep old palaces and towers/ Quivering within the wave's intenser day" . The "old palaces and towers" gives vivid images of ancient Rome and Greece in the readers mind. The speaking voice also uses these images in the sea's dream to show that the natural world and the human social and political world are parallel. He uses soft sounding words to enter the reader into the same dream of the Mediterranean. The "pumice" shows destruction and creation for when the volcano erupts it destroys. But it also creates more new land. The "pumice" is probably Shelley's best example of rebirth and regeneration. The word "Quivering" is not just used to describe the reflection of images in the water. It is also used to show a sense of fear which seems to be the most common mood and emotion in this poem.
In the final stanzas, the wind is transformed from the natural world toward human suffering. Shelley speaks with the wind: "Oh! lift me as a wave, a leaf, a cloud!". He seeks transcendence from the wind and says: "I fall upon the thorns of life! I bleed". He again pleads for the wind: "Drive my dead thought over the universe...to quicken a new birth!". He asks the wind to "Scatter, as from an unextinguished hearth/ Ashes and sparks, my words among mankind!/ Be through my lips to unawakened Earth". The words "unextinguished hearth" represent the poets passion. The "hearth" is also at the centre of the earth which helps make the connection between humanity and nature. Both are constantly trying to reinvent themselves.
At the end of the poem he asks with hope: "If Winter comes, can Spring be far behind?.This sentence could be rewritten substituting the word death, for the word "Winter," and the word rebirth, could take the place of "spring."