Brihat Samhita
मृगमासऽदिष्वष्टौ षट्षोडश विंशतिश्चतुर्युक्ता । विंशतिरथ दिवसत्रयं एकतमऋक्षेण पञ्चभ्यः ॥ २१-३० ॥
Clouds that conceive when the Moon is in any one of the five asterisms referred to in the last stanza in the six months from Mārgaśīrṣa to Vaiśākha, will yield rain respectively for 8, 6, 16, 24, 20 and 3 days continuously.
english translation
mRgamAsa'diSvaSTau SaTSoDaza viMzatizcaturyuktA । viMzatiratha divasatrayaM ekatamaRkSeNa paJcabhyaH ॥ 21-30 ॥
hk transliteration by Sanscript