It’s up to you which you find more convincing, or you could always mention alternative interpretations.

Others have interpreted these lines as suggesting that his love is unlike summer because the season is sometimes afflicted with ‘rough winds’, often seems to be over before it’s begun and (in lines five and six) is sometimes too bright or sometimes too dim, whereas his love is always beautiful. As the sun rises and falls, so too must his love’s beauty. Her beauty (‘the eye of heaven’ – heaven’s perfect creation) was ‘too hot’ and therefore would the perfect ‘gold complexion’ always have to eventually be ‘dimmed’ like the sun gradually falling after midday. The fifth and sixth line I see as the inevitable decline associated with mortality. These two lines show that this perfection of his love is not going to last forever and is confined within a short period of her life. Next ‘summer’s lease’ is described as being ‘too short’, which makes us think about the autumn and the winter to follow that will corrupt and decay the absolute beauty of the summer. Buds are the suggestions of beauty waiting to burst forth as flowers. I read this as a reflection on mortality as the ‘rough winds’ of May shaking the ‘darling buds’ represents the tempestuous spring, which in turn could represent a period where a woman’s beauty and attitude are being refined. I’ll mention two interpretations for lines three to six. However, his love is ‘more lovely’ and ‘more temperature’ meaning that her beauty and her personality/attitude are even more impressive than the summer’s. Suggesting summer as being similar should immediately make you think of connotations such as warm, joyful, bright and beautiful. A rhetorical question opens the sonnet, questioning whether the summer is fair enough to be compared to the poetic voice’s love.

Shakespeare sonnet 18