اللَّهُمَّ اغْفِرْ لِي
Allahummagh-fir li (and any personal du'a)
O Allah, forgive me. (Du'a during rainfall is accepted.)
The Prophet ﷺ said that du'a is accepted at certain times, and one of them is during rainfall. Rain is a manifestation of Allah's mercy descending from the sky — and when mercy is descending, your requests ride up with it. Any personal du'a made while rain is falling carries extra weight. The scholars recommend not wasting a single rainy moment without lifting your hands.
Related Du'as
اللَّهُمَّ إِنِّي أَسْأَلُكَ خَيْرَهَا وَأَعُوذُ بِكَ مِنْ شَرِّهَا
O Allah, I ask You for its good and seek refuge in You from its evil.
Sahihمُطِرْنَا بِفَضْلِ اللَّهِ وَرَحْمَتِهِ
We have been given rain by the grace and mercy of Allah.
Sahihاللَّهُمَّ اسْقِنَا غَيْثًا مُغِيثًا مَرِيئًا مَرِيعًا نَافِعًا غَيْرَ ضَارٍّ عَاجِلًا غَيْرَ آجِلٍ
O Allah, send us rain that is helpful, productive, wholesome, beneficial and not harmful, soon and not delayed.
Sahihاللَّهُمَّ إِنِّي أَسْأَلُكَ مِنْ خَيْرِ مَا سَأَلَكَ عَبْدُكَ وَنَبِيُّكَ مُحَمَّدٌ وَأَعُوذُ بِكَ مِنْ شَرِّ مَا اسْتَعَاذَ مِنْهُ عَبْدُكَ وَنَبِيُّكَ
O Allah, I ask You for the good that Your servant and Prophet Muhammad ﷺ asked You for, and I seek refuge in You from the evil that Your servant and Prophet sought refuge from.
Hasan