The ‘umrah begins by donning of the ihram in the sense that it is obligatory on the pilgrim to put on the ihram for doing ‘umrah at-tamattu‘ at the miqat. However, if he had done the nadhr for donning on the ihram before reaching to the miqat, then that is what he should do.
Mawaqit (pl. of miqat) are the locations specified by the Islamic shari‘ah where the ihram is to be put on. So the miqat for the pilgrim traveling from Medina would be “Masjidu ’sh-Shajarah,” located in Dhi ’l-Hulayfah which is 10 k.m. from Medina and 427 k.m. from Mecca.
The closest miqat for those who arrive at Jeddah by air is “al-Juhfa” which is 204 k.m. from Mecca.
Nadhr for Putting on the Ihram: It is permissible for the pilgrim to do nadhr (vow) for putting on the ihram even at his city’s airport or seaport by saying: “I make a vow for the sake of Allah to put on the ihram for ‘umrah at-tamattu‘ from this location.” And then he can put on his ihram.
It is also permissible for the pilgrim to put on the ihram at Jeddah (72 k.m. from Mecca) by making a similar nadhr when he reaches Jeddah and then there is no need to put on the ihram again.
It is important to mention that most of those who do the nadhr to put on the ihram from their own city put themselves in a situation in which they violate a restriction put on them after donning the ihram—traveling in a covered vehicle during the daytime; and thus they are required to pay the indemnity in form of sacrificing a sheep. The best thing for such a pilgrim is to travel at night time when it is not raining; and it is not that difficult to know the weather forecast.