All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is permissible for you to conduct your son's marriage in the month of Jumada al-Uwla. The marriage contract is not related to one month without another; rather, it is permissible to conduct the marriage contract throughout the months of the year.
In the Pre-Islamic Era of Ignorance, the people had wrong beliefs and customs, as they used to be pessimistic about some particular months during which they do not get married.
Fataawa Dar al-Iftaa’ reads:
‘Urwa narrated that ‘Aa’ishah said: “The Prophet married me in the month of Shawwal and consummated the marriage with me in Shawwaal. And who among the wives of Prophet was dearer to him than I? ‘Urwa said: ‘Aa’ishah, liked that the women (of her family) should enter the houses as brides during the month of Shawwal.” [Al-Bukhaari]
Many people are keen that their marriage contract be conducted on a particular day of the week or in a certain month of the year, which is something that sometimes leads to conflict, or pessimism, or guessing at the unseen about the failure of the marriage if they were to conduct the marriage at other times. This is a habit of the Jaahiliyyah (Pre-Islamic Era of Ignorance) which ‘Aa’ishah refuted and invalidated in the above Hadeeth, as they used to seek bad omen and became pessimistic about the month of Shawwal. They refrained from getting married in this month. Therefore, one should not be pessimistic about conducting the marriage contract at any day or in any month; neither in Shawwal, Muharram, Safar, or any other month of the year. Indeed, there is no Islamic text that forbids conducting the marriage at any time except when one is in the state of Ihraam for Hajj or 'Umrah.” [End of quote]
A person in the state of Ihraam cannot get married or conduct a marriage contract for others until he comes out of the state of Ihraam.
Allah knows best.