The quick reaction team from Tonga's Defence Force had to be called out over the weekend to help with flash flooding.
The Matangi Tonga newsite says a freak storm dumped more than a month's average rainfall in less than 24 hours.
Buildings, including the Australian High Commission, and houses in the main city of Nuku'alofa were flooded after roads turned into rivers.
A duty forecaster, Ofa Taumoepeau, said it was the the greatest rainfall the Kingdom had ever had.
There were no reports of anyone being harmed