Megilla reading

Dear Rabbi, I live in Jerusalem and will be in the north of Israel for Purim and will read the Megilla there with my son and join his family for the Purim Feast. I intend to spend Shusan Purim at home in Jerusalem. Do I have to arrive in Jerusalem in time to read the Megilla in the evening as I will be davening Shaharit, where the Megilla will be read, in the morning? Thank you and Purim Sameah,

Since your planned intention is to be in Jerusalem on the 15th of Adar and you will be there physically before daybreak, then you will have the full obligations of Shushan Purim as well, which will require you also to hear the megilla on the eve of Shushan Purim. (See Shulchan Aruch 688 and mishna brura there 12. Rav Tzvi Pesach Frank zt"l in Kerem Tzion Vol.10, Mikraei kodesh on the laws of Purim of Rav Moshe Harari Shlit"a pgs. 101-103.) Have a happy Purim