‘SUMMER’ word originates from Old English sumor, of Germanic origin; related to Dutch zomer, German Sommer, also to Sanskrit samā ‘year’.
In Sanskrit samā refers to half of the year/ weather/ seassson.
In Ayurveda , Grishma ritu is considered as Aadana Kala of the year, when the sun is in uttarayana(north of the equator).
During uttarayana, the tikshna(sharp)-ushna(hot)-ruksha(dry) properties of the sun and air increases which undoubtedly weakens the saumya bhaava of Earth . These atmospheric changes affect the human body (and all organisms) causing a gradual decrease in vitality and strength.