Is supplication (du'a) answered during rain? And is this hadith weak?

The mentioned wording was not reported as a Hadith. However, it was reported in a Hadith graded as Hasan by Al-Albani: "Seek the answer to supplication when armies meet, when the prayer is established, and when rain falls." In another narration, also graded as Hasan by Al-Albani: "Two are not rejected: supplication at the call (to prayer) and under the rain." Al-Manawi mentioned that what is meant by supplication under the rain is the supplication of one who is beneath it, for it is a time when mercy descends.