This probability is not a constant value and changes from place to place and from season to season. For example, an average annual rainfall of an Indian town of Cherrapunjee is 11777 mm. In Tutunendo, Colombia, this value is 11770 mm. In 1982, Hawaiian Mount Waialeale had 17300 mm of rainfall.
Therefore, the probability that an explorer will find some of the wettest places on earth is the highest in the considered regions.