Dua is Accepted and Answered when the rain falls, when the armies meet and when the Adhan is being called
Narrated Sahel Ibn Sa’ad (radiAllahu anhu): that the Messenger of Allah (salAllahu alayhi wasalam) said: ‘Two will not be rejected, Supplication when the Adhan (call of prayer) is being called, and at the time of the rain’. [Al-Hakim 2: 114, and Abu Dawud #2540, ibn Majah]
‘Seek the response to your du’as when the armies meet, and the prayer is called, and when rain falls’ [reported by Imam al-Shafi' in al-Umm, al-Sahihah #1469]
The time of the rain is a time of mercy from Allah (Subhanahu wa Ta’ala) so, one should take advantage of this time when Allah (Subhanahu wa Ta’ala) is having mercy on His slaves.
In another hadith; ‘When the prayer is called, the doors of the skies are opened, and the du’a is answered’ [al-Tayalisi in his Musnad #2106, al-Sahihah #1413]
In another hadith; ‘When the prayer is called, the doors of the skies are opened, and the du’a is answered’ [al-Tayalisi in his Musnad #2106, al-Sahihah #1413]