Firstly: The Sermon after the Prayer for Rain
A sermon is legislated after the prayer for rain. This is the position of the majority: the Malikis, Shafi`is, and Hanbalis.
Secondly: How to Deliver the Sermon for the Prayer for Rain
Scholars are of two positions regarding how the sermon for the prayer for rain is given:
The first position: Two sermons are given after the prayer for rain. This is the position of the Maliki and Shafi`i schools, one narration from Ahmad, and the position of Muhammad ibn al-Hasan of the Hanafi school and some of the Salaf.
The second position: One sermon is given. This is the position of the Hanbali school, Abu Yusuf of the Hanafi school, and `Abd al-Rahman ibn Mahdi. It is the position of choice of Ibn `Uthaymin.
Thirdly: When the Sermon is Delivered
Jurists differ on when the sermon is to be delivered. There are multiple positions, the strongest of which are two:
The first position: The time for the sermon is after the prayer. This is the position of the majority: the Malikis, Shafi`is, Hanbalis, and Abu Yusuf and Muhammad ibn al-Hasan of the Hanafi school.
The second position: The imam is free to choose to deliver the sermon before or after the prayer. This is according to one narration from Ahmad. It is the position of choice of al-Shawkani, Ibn Baz, and Ibn `Uthaymin.
Fourthly: Reversing the Clothing during the Prayer for Rain The ruling of reversing one’s clothing
It is mustahabb for the imam and the follower  As for a woman, if she were to become uncovered when reversing her clothing, she does not do so. If she would not become uncovered, then the same ruling that applies to men applies to her. to reverse their clothing  Ibn `Uthaymin says: “As for reversing the the ghutrah and shemagh, I do not think this is legislated, for it has not reached us that the turban is reversed, and the ghutrah and shemagh have the same role as a turban.” (Majmu` Fatawa wa Rasa’il al-`Uthaymin, 16/352) Some scholars have limited to the case when one is not wearing a rida’ or something that resembles it. Ibn Baz says: “The sunnah is to reverse the rida’ during the sermon while facing the qiblah. He reverses his rida’, putting its right side on his left if he is wearing a rida’. If he is wearing a bisht (a men’s abaya), he inverts it. If what he is wearing is anything other than a ghutrah, he inverts it. Scholars say this is out of optimism that Allah might transform drought into abundance and adversity into prosperity.” (Fatawa Noor `Ali al-Darb, 13/400) when praying for rain. This is the position of the majority: the Malikis, Shafi`is, and Hanbalis. It is the conclusion of Dawud al-Zahiri and the position of most scholars. When to reverse one’s clothing
The clothing is reversed during the sermon when facing the qiblah in supplication. This is the position of the Shafi`i and Hanbali schools and one position among Hanafis which was selected by Muhammad and Abu Yusuf of the Hanafi school. It is also the case according to one narration from Malik selected by Asbagh. It is the position of choice of Ibn al-Mundhir, al-Shawkani, Ibn Baz, and Ibn `Uthaymin. How to reverse the clothing
Reversing the clothing when praying for rain is by putting the right side of the garment on the left and vice-versa. This is the position of the majority: the Malikis, Shafi`is,  Shafi’is add that he also turns the rida’ upside down. Hanbalis, and a group of the Salaf.
Fifthly: Supplicating to Avert the Harms of Excessive Rain
If rain falls in excess and people are harmed by it, it is sunnah to supplicate Allah asking Him to stop it, and for Him to cause it to be in areas where it brings about benefit and does not harm. This is by agreement of the four schools of jurisprudence.