《晋书·志·第十七章》
永昌元年，春雨下了四十多天，昼夜有雷电五十多天。
永昌元年，春雨四十余日，昼夜雷电震五十余日。
In the first year of the Yongchang era, spring rain fell for more than 40 days, accompanied by thunder and lightning for more than 50 days and nights.