If you have resolved to perform `Umrah on this trip of yours, then you have to enter Ihram for it from Jeddah, because Jeddah is closer to Makkah and is closer than the Miqat.
The Prophet (peace and blessings of Allah be upon him) said, after mentioning the Miqats: “Whoever is closer than that should enter Ihram from his home and the people of Makkah should enter Ihram from there.” (Narrated by Al-Bukhari, 1526)
According to another Hadith: “Whoever is closer than that should enter Ihram from which he intends to head towards Makkah; and the people of Makkah should enter Ihram from Makkah.” (Narrated by Al-Bukhari, 1524)
Shaykh Ibn Baz (may Allah have mercy on him) said:
Jeddah is the Miqat for its people and for those who live there . (End quote from Fatawa Ibn Baz, 17/34)
In Fatawa Al-Lajnah Ad-Da’imah, it says:
With regard to Jeddah, it is the Miqat for the people of Jeddah and for those who live there, if they want to perform Hajj or `Umrah.
And Allah knows best.