How does the speaker use natural imagery in sonnet shall i compare thee to a summers day?

The speaker uses natural imagery in Sonnet 18 to compare the beloved to a summer day, emphasising the beauty and transient nature of both love and life. The poem presents the beloved's beauty as surpassing the finest aspects of nature such as the sun and wind. Through personification, the speaker portrays natural phenomena like the sun, winds and summer as entities that lack the qualities of the beloved, hinting their imperfect and finite nature. The poem concludes with assurance that the beloved's beauty will be preserve in the everlasting lines of poetry, transcending the limitations of time and nature's decay, making the love immortal and resistant to the passage of time.