O Allah, send us rain. O Allah, send us rain. O Allah, send us rain.

Reference:Al-Bukhari 1/224, Muslim 2/613.Hisnul Muslim 170

اللّهُمَّ أغِثْنـا اللّهُمَّ أغِثْنـا اللّهُمَّ أغِثْنـا

Transliteration

Allāhumma aghithnā, Allāhumma aghithnā, Allāhumma aghithnā.

Translation

O Allah, send us rain. O Allah, send us rain. O Allah, send us rain.