Hurricane Ida made landfall near Port Fourchon, La., as a strengthening Category 4 storm with maximum sustained winds of 150 mph. Just shy of a Category 5, Ida delivered a disastrous blow on arrival, coinciding with the 16-year anniversary of Hurricane Katrina.

But Ida held its most devastating punch for its departure, triggering one of the worst urban flood disasters in U.S. history in the Northeast.

The storm and its remnants have caused almost four dozen confirmed fatalities, the majority due to flooding in New Jersey, New York, Pennsylvania and Connecticut. This death toll is expected to rise.

The name Ida will almost surely be retired due to its costs to life and property. It was the sixth named storm to make landfall in the United States during the 2021 season, which is still approaching its peak.

Below, we’ve compiled Ida’s key stats to date.

First (tied) — Ida’s rank in Louisiana’s hurricane history for winds

With sustained winds of 150 mph at landfall, Ida tied the Last Island Hurricane in 1856 and Hurricane Laura in 2020 as the strongest to strike Louisiana, based on wind speed. The sequence of Laura and Ida marked the first time any state has seen two 150 mph hurricane landfalls in consecutive years.

Ida also tied as the fifth-strongest storm to make landfall anywhere in the United States, based on wind speed.

Ida’s registered a peak wind gust of 172 mph, near the landfall point in Port Fourchon.

3 days — Ida went from a mass of showers to a strong Category 4 hurricane

In a warming world, it is expected that more tropical systems will feed off warmer water to undergo rapid intensification, defined as at least a 35 mph gain over 24 hours. Ida turned from showers to a monster 150 mph hurricane in three days. In its final day over water, Ida gained 65 mph, tying it with Humberto in 2007 for the most significant intensification burst into landfall, according to the Associated Press.

Six — Number of states where tornadoes touched down

Tornadoes are a typical aspect of tropical systems, especially when storms come out of the Gulf of Mexico and meander over land afterward. At least six states, stretching from the Mississippi coast to Cape Cod in Massachusetts, saw tornado touchdowns. Several people were injured in Alabama shortly after landfall.

On Sept. 1, Ida’s remnants delivered a regional tornado outbreak to the northern Mid-Atlantic. Several tornadoes in this part of the event were unusually strong for tropical remnants, probably in part due to the storm transitioning to an extratropical system featuring a warm front and a cold front.

Among the tornadoes assessed thus far, the one that passed through Mullica Hill, N.J., about 10 miles south of Philadelphia, received an EF3 rating on the 0 to 5 scale for intensity, the strongest to hit the state in 31 years. Farther south, an EF2 struck portions of Annapolis, the capital of Maryland.

Seven — Number of major hurricanes that have hit the Lower 48 and Puerto Rico since 2017

Between Hurricane Wilma in late 2005 and Hurricane Harvey in 2017, no hurricanes higher than a Category 2 hit the United States or Puerto Rico. But including Harvey, there have been seven Category 3-plus “major” hurricane strikes since. In addition to the rare Category 5 in Michael, Ida was the fifth Category 4 of the bunch to make landfall; four of them came ashore along the Gulf Coast.

2020 marked a record-breaking year, with 11 U.S. landfalls of named tropical systems. Ida was the sixth named storm to make landfall in the country in 2021, setting up another high landfall year for the United States

9 hours — Time from landfall to Ida dropping below Category 3

Most hurricanes rapidly weaken once they hit land, but Ida remained a major hurricane for nine hours. Ida made first landfall around 12:55 p.m. Five hours later, it was still a Category 4 with 130 mph winds. It didn’t drop below major hurricane status until 9 p.m., finally becoming a tropical storm sometime before 4 a.m. the day after landfall.

This super slow decrease in intensity was probably due to southern Louisiana marshlands being overcome with warm surge water, plus the fact that it was strengthening until it came ashore.

10-plus feet — Storm surge inundated coastal areas

Storm surge heights between about eight feet and 10 feet have been observed. It is likely that higher surge occurred in areas with no easy way to measure it, and post-storm analysis will seek out those heights. Maximum forecasts were for a surge of 12 to 16 feet. Waves offshore were measured by satellite to be as high as 38 feet.

The Mississippi River reversed flow for around three hours as surge was pushed out of the ocean, but the major levee improvements in New Orleans after Katrina withstood the test.

17 inches — Ida’s rain flooded areas around New Orleans, Philadelphia and New York City

Radar estimates of up to about 17 inches were recorded just west of New Orleans. A station eight miles south-southeast of Slidell, La., tallied 15.73 inches, the maximum recorded by a ground station thus far, with 10-inch-plus numbers common in that region.

As Ida moved toward the Northeast, a widespread three to eight inches of rain was reported from northern Maryland through southern New England.

Newark picked up 8.44 inches, its wettest day on record, with Central Park in New York City coming in at 7.19 inches, its fifth-wettest day. Record-setting rainfall rates of three inches or more in an hour caused devastating flooding.

The torrents triggered flash-flood emergency declarations from south-central Pennsylvania to southern New England, including the first issued in New York City.

River levels surged because of the deluge. The Schuylkill River in Philadelphia rose to 16.35 feet, its second-highest level on record. Evan Dethier, a postdoctoral fellow at Dartmouth College, found seven rivers in the Northeast recorded all-time peak floods while 55 recorded floods ranking in the top five.

930 millibars — Ida central pressure at landfall

Ida was the rare tropical cyclone that was at its strongest as it came ashore. The 930 millibars also ties Ida for the ninth-lowest pressure of a landfalling storm in U.S. history. Only Katrina was “deeper” at landfall in Louisiana, with 920 millibars of pressure, although in that case it was unwinding from peak.

1.5 million — Customers who lost power

More than 1 million customers lost power in Louisiana alone, including most of New Orleans. A major transmission line was downed across the Mississippi River near the city, with a timetable for fixing it still unclear. It’s the second-largest power outage in Louisiana since 2000, and could leave some residents without power for weeks in hot weather, which will only increase human suffering and risk.

In Mississippi, roughly 100,000 customers lost power. And another quarter of a million lost power in the Northeast as Ida’s merciless remnants swept by. Several other states also saw outages to a lesser extent.

Tens of billions of dollars — economic damages

Steve Bowen, a meteorologist at reinsurer AON, stressed it will take time to get a full assessment of the economic damages from the storm, but that “the best estimate to-date is a direct economic cost well into the tens of billions.”

“The original footprint in Louisiana was already significant on its own, but the catastrophic flooding in the Northeast has added an entirely new complex component to the relief, recovery, and assessment process,” he wrote to the Capital Weather Gang.

In addition to the damages from wind, surge, urban flooding and tornadoes, the storms shuttered cities and towns. Long-term power outages will extend some closures, as will waiting for floodwater to recede.

“[T]he prolonged shut down of businesses due to power outages or other direct impacts from Ida will lead to ongoing net loss business interruption,” Bowen wrote. “The event may finally be over, but damage costs will continue to rise in the near future.”

Jason Samenow and Kasha Patel contributed to this report.