The Compendium of Kāśyapa 8.7.4

8.7.4

cayaprakopapraśamāḥ pittasya prāvṛḍādiṣu
śleṣmaṇaḥ śiśirādyeṣu vāyorgrīṣmādiṣu triṣu

The accumulation, aggravation, and pacification of pitta occur in the three [seasons] beginning with the early rains; / of kapha, in those beginning with the late winter; and of vāta, in those beginning with the summer.