Away from his homeland in the west, the speaker yearns to go back home. With the blowing of the warm west wind, the cherished memories of his native place in the month of April are instantly evoked. They turn him nostalgic and upset.
I never hear the west wind but tears are in my eyes.
For it comes from the west lands, the old brown hills.
The west wind is the harbinger of spring. After the harsh winter, the warm west wind is soothing. It's perception reminds the speaker of the pastoral beauty of his native place, where he longs to return.
During this time, the birds begin to chirp, daffodils and “apple orchards blossom,” "the air’s like wine," “there is cool green grass there, where men may lie at rest”, thrushes can be heard “fluting from the nest,” “the young corn is green,” the rabbits run,” the sky is blue and the clouds are white, both the sun and the rain are warm and the buzzing of bees is like “song to a man’s soul” and “fire to a man’s brain.”
These pleasant memories of his native land make him all the more homesick and wistful.
The phrases "tired feet," "bruised hearts" and "aching eyes" suggest the pain and discomfort that afflict the speaker away from his motherland. It seems to him as if the west wind is insisting on his returning home.
"Will ye not come home brother? ye have been long away,”
The urge to go back home is so strong in the speaker that he can't prolong his stay in the alien land any more. He makes up his mind to set off for the place he actually belongs to:
It's the white road westwards is the road I must tread
To the green grass, the cool grass, and rest for heart and head,
To the violets, and the warm hearts, and the thrushes' song,
In the fine land, the west land, the land where I belong.