All of Puerto Rico was without power Sunday as Hurricane Fiona hit the island, bringing with it massive amounts of rain and catastrophic flooding.

The storm made landfall at 3:20 p.m. EST on Puerto Rico’s southern coast, with maximum sustained winds of 85 mph, according to the US National Hurricane Center.

“It’s time to take action and be concerned,” Nino Correa, Puerto Rico’s emergency management commissioner, said of the hurricane, which blanketed the entire island with its clouds.

The tempest was estimated to dump “historic” levels of rain, up to 25 inches of rain, with most areas seeing between 12 and 16 inches, forecasters said.

“These rains will produce life-threatening flash flooding and urban flooding across Puerto Rico and the eastern Dominican Republic, along with mudslides and landslides in areas of higher terrain,” the NHC said.

Fiona hit shortly after the island’s governor, Pedro Pierluisi, confirmed the mass blackout and activated the National Guard.

It was unclear when power would be restored as “current weather conditions are extremely dangerous and are hindering our capacity to evaluate the complete situation,” said Luma, the company that operates the island’s power transmission and distribution.

Puerto Rico’s 3.3 million residents might have to wait several days to regain electricity, the company warned.

President Biden on Sunday morning made an emergency declaration for Puerto Rico, allowing FEMA to prepare to deal with Fiona’s aftermath.

Fiona, then a tropical storm, killed one man in the French territory of Guadeloupe on Friday when his home was washed away by floods. His body was discovered on Saturday.

The storm was upgraded to a Category 1 hurricane on Sunday as it reached sustained winds of 80 mph.

The National Weather Service said Saturday that the Blanco River in the island’s southeast is already overflowing and told those who live nearby to flee to higher locations, and other rivers began to crest Sunday.

“What worries me most is the rain,” forecaster Ernesto Morales with the NWS said.

Public schools and government agencies will be closed on Monday, and Gov. Pierluisi has deployed the country’s national guard. The island’s main airport and its ports were closed Sunday. All health centers and hospitals are running on generators, some of which have already failed, island officials said.

The area expected to be hit by the hurricane is still reeling from a string of earthquakes in 2019 that caused significant destruction.

Fiona made landfall on the 33rd anniversary of Hurricane Hugo, a Category 3 storm that killed 67 people, including eight in Puerto Rico.

It also struck just two days before the five-year anniversary of Hurricane Maria, the Category 5 storm that destroyed Puerto Rico’s power grid and killed around 3,000 people.

The country’s grid, which has already failed, has remained particularly tenuous since Maria.

“I think all of us Puerto Ricans who lived through Maria have that post-traumatic stress of, ‘What is going to happen, how long is it going to last and what needs might we face?’ ” said local Danny Hernández.

Hernández, who works in San Juan, stocked up at a local supermarket before the storm hit.

“After Maria, we all experienced scarcity to some extent,” he said.

Fiona is the Atlantic basin’s sixth named storm of the season. The eastern portion of the Dominican Republic is also expected to be badly hit.

With Post wires