Rather than give you an in depth analysis, I will aim to provide you with a general summary of this excellent poem. After all, part of the fun of poetry is analysing it yourself! So to give a brief introduction, this poem is part of a sequence of poetry that remembers Hardy's marriage to Emma and his love for her. It is one of many elegies that he wrote after her death as he tries to come to terms with his grief and the loss of her.
This poem thus begins with Hardy hearing Emma's voice calling him, saying that she has reverted to her earlier self which he loved so much. However, the poem raises serious doubts about whether it is really her or not. Hardy says he wants to see her as she was in Cornwall in the earliest days of their courtship. But already he has lost his confidence in her reality. Perhaps it was just the sound of the breeze. Emma is gone forever and he is a desolate old man. In my opinion, this is one of the bleakest poems in the sequence of elegies. The last stanza, from my perspective, is incredibly masterful as we are left with the picture of a grief stricken old man trying to move on, both physically and emotionally, in his life:
Thus I; faltering forward,
Leaves around me falling,
Wind oozing thin through the thorn from norward,
And the woman calling.
We are left with a picture of a man haunted by the possibility of hearing his dead wife and trying to press on with great difficulty. Note the alliteration that gives this stanza its structure in "faltering forward" and "falling" and then "thin through the thorn" which present a very bleak picture. The poem ends where it began - with the tantalising yet haunting voice of his love on the wind and the speaker of the poem struggling to live with the loss of his wife.
So any analysis will want to consider how the setting and in particular the weather ties in with the mood, and also it will want to focus on the speaker and his state of mind as expressed in the poem.