The cyclone warning for Tonga has now been cancelled but a strong wind warning has been issued for Tongatapu 'Eua, Tele-ki-Tonga and Tele-Ki-Tokelau land areas and coastal waters.
Tonga's Meteorological Service director, Ofa Fa'anunu, said the decision to downgrade the cyclone followed satellite observations early Sunday morning.
He said the system was now to the east of the main island Tongatapu, and heading south and out to open ocean.
The northern islands of Ha'apai and Vava'u are still reporting gusts of over 90 km/h but Mr Fa'anunu said that would start to decrease.
He said informal reports from family and friends on Vava'u say there was damage to trees, vegetation and agricultural.
"No structural damages have been reported just yet but Tonga's Emergency Management Office would probably have more information in the next day or two," Ofa Fa'anunu said.