The Prophet ﷺ said, "There is no contagion, no ill omen in the month of Safar, no omen in the owl, and no rain brought by the stars."
وبهذا الإسناد أن النبي ﷺ قال لا عدوى ولا صفر ولا هامة ولا نوء
Its chain of transmission is sahih. It has already appeared at 7609, and Muslim narrated it in 4/1742, number 2220, in the Book of Greetings, "There is no contagion and no bad omen."