Tropical Storm Ian churned in the Caribbean on Sunday morning, threatening to ramp up to a hurricane and lash at Florida in the coming days — as Canada was left reeling from Fiona, which swept away buildings and homes and left hundreds of thousands of people in the dark.

Gov. Ron DeSantis declared a state of emergency in all of Florida and urged residents to prepare for a fierce storm as weather tracking models showed Ian taking aim at either its Gulf of Mexico coast or panhandle region.

“We’re going to keep monitoring the track of this storm. But it really is important to stress the degree of uncertainty that still exists,” DeSantis said at a news conference Sunday, warning that “even if you’re not necessarily right in the eye of the path of the storm, there’s going to be pretty broad impacts throughout the state.”

The grim forecast led President Biden, who declared a federal state of emergency for the state, to postpone a Tuesday trip to Fort Lauderdale and Orlando, and caused NASA to again delay its Artemis 1 moon launch from Cape Canaveral.

News outlets reported runs on water, generators and other supplies in some areas of the Sunshine State.

Former hurricane Fiona, meanwhile, slammed into Nova Scotia Saturday morning as a “devastating” post-tropical cyclone, sending buildings into the ocean, collapsing homes and toppling “an incredible amount” of trees and power lines, provincial Premier Tim Houston told CNN.

The Canadian Armed Forces were deployed to the region to assist with the ongoing state of emergency caused by one of the strongest storms ever to wallop the nation.

“People have seen their homes washed away, seen the winds rip schools’ roofs off,” Prime Minister Justin Trudeau said, according to CNN. “And as Canadians, as we always do in times of difficulty, we will be there for each other.”

More than 350,000 customers were without power in Nova Scotia and Prince Edward Island at 8:30 a.m. Sunday. Over 750,000 electric customers remained in the dark in Puerto Rico, a week after Fiona ripped through the island territory at hurricane strength, killing at least 16, according to Poweroutage.com.

In Halifax, about 100 people were reportedly forced to seek shelter after winds of up to 105 miles per hour collapsed the roof of an apartment complex.

Further north in Newfoundland, record tides and heavy rain submerged cars and ripped structures from their foundations, footage showed.

A woman was pulled to safety from the water after her house collapsed as first responders grappled with electrical fires and downed trees and powerlines, according to the report.

“We’ve got a total war zone here, we’ve got destruction everywhere,” Port aux Basques Mayor Brian Button said in a Saturday night video update where he warned of additional storm surges.

Even as the storm weakened and passed, eastern Canada was expected to be besieged by more flooding Sunday from storm surge and heavy rain, officials warned.

Elsewhere, Ian was rumbling in the southwestern Caribbean Sea on Sunday. It was expected to become a category 4 hurricane as it tore through the Gulf of Mexico Tuesday or Wednesday, threatening Cuba and Florida, according to the National Weather Service.

Here’s everything to know about Hurricane Ian:

Hurricane conditions were expected in Grand Cayman by early Monday and in parts of western Cuba Monday or early Tuesday, according to the report.

Up to 12 inches of rain could add to a life-threatening storm surge of up to 14 feet higher than normal level in parts of Cuba and up to 8 inches or rain could soak Jamaica and the Cayman Islands, the National Hurricane Center said.

Ian’s circulation was set to grow intensely in the Gulf before it reached Florida later in the week.

With Post wires