Charak Samhita
भूबाष्पान्मेघनिस्यन्दात् पाकादम्लाज्जलस्य च। वर्षास्वग्निबले क्षीणे कुप्यन्ति पवनादयः ॥३४॥
In this season, due to evaporating vapors from the Earth, rainfall and acidic transformation of water, the agni is weakened, thus leading to the further vitiation of vata and other dosha.
english translation
bhUbASpAnmeghanisyandAt pAkAdamlAjjalasya ca। varSAsvagnibale kSINe kupyanti pavanAdayaH ॥34॥
hk transliteration by Sanscript