Performing tawaf during rain is entirely boleh and is, in fact, considered a specially blessed time by scholars. There is no scholarly prohibition or dislike associated with tawaf during rainfall. Nabi (shallallahu alaihi wa sallam) identified rainfall as one of the times when doa is more likely to be answered, making tawaf during rain an excellent opportunity to combine two blessed acts — circumambulating the Kabah and supplicating during rainfall.
Sheikh Ibn Baz encouraged jamaah haji to take advantage of rain during their ibadah haji, 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 tawaf should be postponed due to rain. The Permanent Committee similarly confirmed that tawaf during rain is valid and carries no special restrictions.
From a practical standpoint, scholars note that the Mataf (tawaf area) can become slippery during rain, and jamaah haji — especially the elderly and those with mobility issues — should exercise caution. The Masjidil Haram administration takes measures to ensure safety during such times. Pilgrims may also perform tawaf on the covered upper floors if they prefer to avoid the rain, and this is equally valid. Using an umbrella during tawaf is also boleh.