Is rain during Chodesh Nisan considered a bad siman?
Answer:
Chazal do not see rain in Nissan as a bad omen. The Mishnah states that rains after Nissan are a bad omen (siman kelalah), but Rishonim (see Ran, Taanis 1:1; Ra’av and Tosafos Yom Tov, Taanis 1:7) write that this applies only to post-Nissan rainfall in years when there was no rainfall prior to Nissan. If there was rain in the winter months, the post-Nissan rain would not be considered a negative omen.