summary and interpretation of Blow blow thou winter wind

The poem entitled 'Blow! Blow! Thou Winter Wind' is a song sung by the character named Amiens in the drama written by William Shakespeare. Amiens is one of the lords who have by their own choice come with Duke Senior, who had been banished by his brother. Amiens sings this song commenting upon the ways of the world, and human ingratitude which is more biting than the piercing cold winter wind. 
The poet in the very beginning addresses the winter wind and says that it can blow as much hard as it likes because it is not so harsh and rude like man's nature of being ungrateful. The attack of the winter wind is not so sharp because it is not visible although it is bitingly cold. 
The poet asks the frosty sky to freeze because it won't cause him deep pain as caused by his friends who forget his favours instead of being thankful. The poet says that although the waters are frozen they don't cause sharp pain like one caused by his friend, who doesn't even bother to remember him. Thus, the frozen faces of the world are more painful than the frozen waters.We should always be singing throughout the year like 'holly' (an evergreen plant). The poet here says that the friendship is only a pretence and loving is nothing but absurdity and foolery. He again tells that life is very wonderful and should be fully enjoyed. It is like a song and should be sung. 
The poet here projects a harsh reality through his song. The celebrated poet Shakespeare is known for his wise words. He is his same self here. His statements are weighty, pithy and precisely correct.

“Blow, Blow, Thou Winter Wind” is a poem from the Shakespeare play As You Like It. This poem is an example of a type of figurative language called personification. When writers personify, they give human characteristics to their subject.

If you look carefully at this poem, you will see that it is not actually about the winter wind at all. Shakespeare reveals his true meaning in the middle of the poem with the line “Most friendship is feigning, most loving mere folly.” He is saying that people are often not true to their “friends” or “loved ones,” or that their friendship or love is not real. He uses the idea of a winter wind, which could be painful, to communicate how much more painful the false love and friendship is. So, when he says of the wind, “Thy tooth is not so keen,” he means that the pain caused by the wind (in the case, the wind’s metaphorical “tooth” can cause pain by biting) is not as hurtful as the emotional pain of the untrue friend or lover.

The personification is evident in the description of the wind. It is said to have a “tooth” and “breath.” It is also said to be less “unkind” than the untrue friend. These are human attributes rather than aspects of the wind. He uses the wind as a contrast to an aspect of human life; therefore, he needs to personify it.

This poem is from Shakespeare’s play As You Like It. This is a song, sung by Amiens. He is a lord, who chose to follow Duke senior, banished by his brother. In this song he comments upon the ways of the world and the human rudeness and ingratitude, which is more biting than the winter wind.

In the beginning of the poem Amiens addresses the winter wind: it can blow as strongly as it wills, but it cannot be as biting as human society.

The second part he partly accuses his friends for forgetting his favors and not being thankful. Wind can freeze him, but it won’t be so painful as the behavior of his friends.

The poet here says that the friendship is only a pretence and loving is nothing but absurdity and foolery. He again tells that life is very wonderful and should be fully enjoyed. It is like a song and should be sung.

[Postscript: Different interpretations are given! So you can choose at your own way]