Hisnul Muslim 168

Upon hearing thunder

سُبْحَانَ الَّذِي يُسَبِّحُ الرَّعْدُ بِحَمْدِهِ وَالْمَلَائِكَةُ مِنْ خِيفَتِهِ

Subhaanal-lathee yusabbihur-ra'du bihamdihi walmalaa'ikatu min kheefatihi.

Glory is to Him Whom thunder and angels glorify due to fear of Him.