Tonga appears to have escaped casualties or major damage to infrastructure after being lashed by Cyclone Ula yesterday.
Media reported the category 3 system brought heavy rain and winds of 150km/h and gusts up to 200km/h to the region.
A state of emergency issued only for Vava'u and Ha'apai was being reviewed while the cyclone stays in Tongan waters.
Matangi Tonga Online reported climate experts believe a lack of moisture to drive the system prevented it from intensifying into a devastating category 4 or 5 storm.
Deputy Prime Minister Hon Siaosi Sovaleni, chairman of the National Emergency Management Committee, said no casualties were reported by police who had checked with the hospital and verified with town officers in Vava'u.
He said the committee would have a better idea of the damage when people went to look at their houses.
"We had 11 evacuation centres, and more than 390 people were relocated to these evacuation centres. About 3.21am electricity was shut down for safety reasons."
He said there were reports that many trees had fallen.
"We were expecting the worst last night as it was heading straight at Vava'u and fortunately it got diverted a little. We are lucky. We are very happy that there are no casualties," he said.
Bronwyn Haling, an Australian who is staying at the Ha'apai Beach Resort, said she believed the worst of the storm hit the island about 4am and was still coming in squalls later yesterday.
"Some people staying elsewhere were evacuated to a local school to be safe and others transferred to another resort," she said. "The wind was pretty scary overnight but had calmed down a good bit by about 10am.
"We were well locked down and there was no real damage done or trees down, but people remember the last cyclone in 2014 and were well prepared. The cyclone shutters were closed at the resort and fresh water pumps were disconnected to protect the supply.
"We are hoping the worst of it has now passed."
Cyclone Ula was expected to weaken as it reached Fiji's Lau group today.
As the storm intensified yesterday international aid organisations geared up to help.
Oxfam New Zealand is ready to send emergency staff to Tonga to assess the situation on the ground and identify the most urgent needs.
In January 2014, tropical Cyclone Ian ripped through Tonga's Ha'apai islands, destroying buildings and homes. Oxfam provided access to safe water, ensuring sanitation needs were met, and helped people recover their livelihoods so they could earn a living and support themselves and their families.
Cyclone Ula earlier caused property damage on low-lying Tuvalu, ripping roofs off houses and destroying plant crops.