Making Du’a When It Rains: Recommended?
Question

1. What is the du‘a to be said when rain falls, and when seeing thunder and lightning?
2. What is the hadith that indicates that du‘a at the time of rainfall will be answered?
Praise be to Allah.Making du’a when it rains
It was narrated from ‘Aishah (may Allah be pleased with her) that when the Messenger of Allah (blessings and peace of Allah be upon him) saw rain, he would say: “Allahumma sayyiban nafi‘an {O Allah, (make it) a beneficial downpour).” (Narrated by al-Bukhari, 1032)
According to a version narrated by Abu Dawud (5099), he used to say: “Allahumma sayyiban hanian (O Allah, (make it) a wholesome downpour).” Classed as sahih by al-Albani.
The word sayyib (translated here as downpour) refers to rain that flows. Allah, may He be exalted, says (interpretation of the meaning): “Or like a heavy downpour [sayyib] from the sky” [al-Baqarah 2:19] (Ma‘alim as-Sunan by al-Khattabi, 4/146)
When it rains, expose your body to the rain
It is mustahabb to expose oneself to the rain and let some of it flow over one’s body, because of the proven report from Anas (may Allah be pleased with him) who said: When we were with the Messenger of Allah (blessings and peace of Allah be upon him) it rained. The Messenger of Allah (blessings and peace of Allah be upon him) lifted part of his garment so that the rain could fall on him. We said: O Messenger of Allah, why did you do that? He said: “Because it has just come from its Lord, may He be glorified and exalted.” Narrated by Muslim (898).
What to say when the rain grows severe
When the rain grew severe, the Prophet (blessings and peace of Allah be upon him) said: “Allahumma hawalayna wa la ‘alayna; Allahumma ‘ala al-akami wa’z-zirabi, wa butun al-awdiyah wa manabit ash-shajar (O Allah, (let the rain fall) around us and not upon us, O Allah, (let it fall on) the small mountains and hillocks, the valley bottoms and places where trees grow).” Narrated by al-Bukhari (1014).
Is there a du’a that you can say when hearing thunder and seeing lightning?
With regard to du‘a when hearing thunder, it is proven from ‘Abdullah ibn az-Zubayr (may Allah be pleased with him) that when he heard thunder he would stop speaking and would say: Subhan alladhi yusabbih ar-ra‘du bi hamdihi wa'l-malaikatu min khifatihi (Glory be to the One whom the thunder glorifies and praises, and so do the angels because of His Awe) [cf. ar-Ra‘d 13:13]. Then he would say: This is a stern warning to the people of earth. Narrated by al-Bukhari in al-Adab al-Mufrad (723); Malik in al-Muwatta (3641). Its isnad was classed as sahih by an-Nawawi in al-Adhkar (235) and by al-Albani in Sahih al-Adab al-Mufrad (556).
We do not know of any marfu‘ report from the Prophet (blessings and peace of Allah be upon him) concerning that.
Similarly, there is no proven dhikr or du‘a from the Prophet (blessings and peace of Allah be upon him) for seeing lightning, as far as we know. And Allah knows best.
Is it true that du’a gets accepted at the time of rain?
The time when rain comes down is a time of divine bounty and mercy from Allah to His slaves, when the means of goodness are abundant, and it is a time when it is thought that du‘as will be answered .
It says in the marfu‘ hadith of Sahl ibn Sa‘d that the Prophet (blessings and peace of Allah be upon him) said: “Two (du‘as) are not rejected: du‘a at the time of the call to prayer and du‘a at the time of rain.” Narrated by al-Hakim in al-Mustadrak (2534); at-Tabarani in al-Mu‘jam al-Kabir (5756); classed as sahih by al-Albani in Sahih al-Jami‘ (3078).
For more about rain-related fiqhi issues, please see these answers: 31172 , 106287 , and 182416 .
And Allah knows best.