How to interpret the ahadith about joining two prayers due to rain?

One day (in winter) an imam came from the next close city (about 20-25kms away) and held the Friday Khotba in the mosque I was at. Afterwards he said we will inchallah pray the 'Asr now as it is raining and as I'm travelling you'll need to go ahead and complete the 4 raka's. I was asking myself first he is not travelling -but that's his matter- as he comes from a close city and secondly how could he say it was raining while the rain actually stopped and was not even heavy? Does this mean we can join prayers just because it was raining at that day even if it was no more raining? So my question is how careful or how extensively can one construe or interpret the ahadith (See for example the hadith displayed below) allowing joining two prayers due to rain? > Ibn 'Abbas reported that the Messenger of Allah (ﷺ) combined the noon prayer with the afternoon prayer and the sunset prayer with the 'Isha' prayer in Medina without being in a state of danger or **rainfall**. And in the hadith transmitted by Waki' (the words are): " I said to Ibn 'Abbas: What prompted him to do that? He said: So that his (Prophet's) Ummah should not be put to (unnecessary) hardship." And in the hadith transmitted by Mu'awiya (the words are):" It was said to Ibn 'Abbas: What did he intend thereby? He said he wanted that his Ummah should not be put to unnecessary hardship." (Sahih Muslim ) What are the positions of scholars on this matter?