Sahih al-Bukhari
Sahih al-Bukhari 666
It is permissible to pray at one's dwelling during rain or if there is a genuine excuse
Arabic hadith text
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، قَالَ أَخْبَرَنَا مَالِكٌ، عَنْ نَافِعٍ، أَنَّ ابْنَ عُمَرَ، أَذَّنَ بِالصَّلاَةِ فِي لَيْلَةٍ ذَاتِ بَرْدٍ وَرِيحٍ ثُمَّ قَالَ أَلاَ صَلُّوا فِي الرِّحَالِ. ثُمَّ قَالَ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَيَأْمُرُ الْمُؤَذِّنَ إِذَا كَانَتْ لَيْلَةٌ ذَاتُ بَرْدٍ وَمَطَرٍ يَقُولُ أَلاَ صَلُّوا فِي الرِّحَالِ.
Translation
Narrated Nafi`
Once on a very cold and stormy night, Ibn `Umar pronounced the Adhan for the prayer and then said, "Pray in your homes." He (Ibn `Umar) added. "On very cold and rainy nights Allah's Messenger (ﷺ) used to order the Mu'adh-dhin to say, 'Pray in your homes.' "