Imām An-Nasaʾī رحمه الله has narrated a ḥadīth on the authority of ʿĀ’ishah رضي الله عنها that the Prophet ﷺ would recite the following when it would rain:

اللَّهُمَّ اجْعَلْهُ صَيِّبًا نَافِعًا

“Allāhum-maj ʿal-hu ṣay-yiban nā-fiʿan”

“O Allāh, make it a fruitful rainfall”

Ibn Mājah رحمه الله has narrated the same hadith with a slight difference:

اللَّهُمَّ اجْعَلْهُ صَيِّبًا هَنِيئًا

“Allāhum-maj ʿal-hu ṣay-yiban hanī’an”

“O Allāh, make it a pleasant rain”