Prophet (SAW)'s Prayers Dua For Rain

Recite:

اللَّهُمَّ أَغِثْنَا

"O Allah, listen to our plea (request)". (Muslim)

Alternate dua for rain

اللَّهُمَّ أَنْزِلْ عَلَى أَرْضِنَا زِينَتَهَا وَسَكَنَهَا

"O Allah, beautify our land (i.e. let flowers grow) and give us peace (ease)". (Abu Awonia)

When it rains, seek forgiveness, as pardon plays a major role.