When the Prophet ﷺ saw a cloud formation in the sky, he left work, even if he were at prayer, and then would say: "O Allah! I seek refuge in Thee from its evil. " If it rained, he would say: "O Allah! send a beneficial downpour."
أَنَّ النَّبِيَّ ﷺ كَانَ إِذَا رَأَى نَاشِئًا فِي أُفُقِ السَّمَاءِ تَرَكَ الْعَمَلَ وَإِنْ كَانَ فِي صَلاَةٍ ثُمَّ يَقُولُ اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنْ شَرِّهَا فَإِنْ مُطِرَ قَالَ اللَّهُمَّ صَيِّبًا هَنِيئًا