Performing الطواف during rain is entirely جائز and is, in fact, considered a specially blessed time by scholars. There is no scholarly prohibition or dislike associated with الطواف during rainfall. النبي (صلى الله عليه وسلم) identified rainfall as one of the times when دعاء is more likely to be answered, making الطواف during rain an excellent opportunity to combine two blessed acts — circumambulating the الكعبة and supplicating during rainfall.
الشيخ ابن باز encouraged الحجاج to take advantage of rain during their الحج, noting that it is a manifestation of Allah's mercy and a time when the gates of heaven are opened. He stated there is no basis for the claim that الطواف should be postponed due to rain. The اللجنة الدائمة similarly confirmed that الطواف during rain is valid and carries no special restrictions.
From a practical standpoint, scholars note that the Mataf (الطواف area) can become slippery during rain, and الحجاج — especially the elderly and those with mobility issues — should exercise caution. The المسجد الحرام administration takes measures to ensure safety during such times. Pilgrims may also perform الطواف on the covered upper floors if they prefer to avoid the rain, and this is equally valid. Using an umbrella during الطواف is also جائز.