The Compendium of Caraka 1.6.6

1.6.6

tatra ravirbhābhirādadāno jagataḥ snehaṃ vāyavastīvrarūkṣāścopaśoṣayantaḥ śiśiravasantagrīṣmeṣu yathākramaṃ raukṣyamutpādayanto rūkṣān rasāṃstiktakaṣāyakaṭukāṃścābhivardhayanto nṛṇāṃ daurbalyamāvahanti //

There, the sun taking away the unctuous moisture of the world by its rays, and the winds being intense and dry drying it up, producing dryness in succession during śiśira, vasanta, and grīṣma, and increasing the dry tastes—bitter, astringent, and pungent—bring about weakness in human beings.