Is the Sunnah in the prayer for rain to be performed in the open prayer ground or in the mosque?

Question:
He says: Honorable Shaykh, may Allah grant you success, is the Sunnah to pray in the open prayer ground or in the mosque?

Answer:
The Sunnah is like that of the festival. The Sunnah for it is that it is like the festival prayer, performed in the open prayer ground in the desert. This is the Sunnah. It is permissible for them to pray in the mosques if they need to, such as on days of severe cold or when the people are numerous and in need of more prayer spaces. There is no objection to praying it in the mosques when there is a need.