Abu Hurairah (may Allah be pleased with him) narrates that the Messenger of Allah (peace be upon him) once went out to pray for rain, so he led us in two rak‘ahs and recited aloud, but he did not have the adhan or iqamah called.
Hadith Referenceصحيح ابن خزيمه / جماع أبواب صلاة الاستسقاء وما فيها من السنن / 1409