El Niño has met its demise.

The much-hyped ocean-atmosphere oscillation was declared dead by the National Weather Service today. The pool of unusually warm water in the eastern tropical Pacific Ocean, the telltale indicator of El Niño, has cooled to nearly normal.

“We’re sticking a fork in this El Niño and calling it done,” writes NOAA climate analyst Emily Becker on its El Niño blog.

But this year’s El Niño, among the strongest on record, will long be remembered for profoundly altering weather extremes in parts of the world while pushing the planet’s temperature to shocking record highs, with devastating consequences.

The Earth’s temperature in 2015 became the warmest on record by a landslide, largely because of the excess heat passed from the tropical Pacific into the atmosphere — superimposed on the long-term climate warming from rising greenhouse gas concentrations.

The warming effect of El Niño has carried into 2016, with every month so far ranking the warmest on record. 2016 has started off so unusually warm that climate scientists say it is almost certain to beat 2015’s record.

The warming inflicted on the tropical ocean waters has enhanced a coral bleaching event described as one of the worst ever observed. While the long-term climate warming is thought to have initiated the bleaching, El Niño intensified the damage.

Australia’s Great Barrier Reef was hit hard. “Only four reefs out of 520 [observed] had no bleaching,” Terry Hughes, director of the Australian Research Council Centre of Excellence for Coral Reef Studies, told Science magazine.

Mass bleaching has destroyed as much as 35 percent of the coral on the northern and central Great Barrier Reef, a major blow to the World Heritage Site. (Reuters)

The damage to the corals around the island of Kiritimati in the Pacific, about 1,000 miles south of Hawaii, was called a “horror show” by researcher Julia Baum of the University of Victoria.

While El Niño dulled the vibrant corals, it intensified massive wildfires in Indonesia, which emitted more carbon dioxide to the atmosphere than Japan does in a year by burning fossil fuels, according to The Washington Post’s Chris Mooney. In part because of the pulse of carbon dioxide from Indonesia, atmospheric concentrations shot up to a record this May of 407.7 parts per million (ppm).

The Indonesian wildfires were spurred by El Niño-induced drought in the region. While El Niño warmed the eastern tropical Pacific Ocean, it cooled the western tropical Pacific, leading to sinking air motions that quashed rainfall.

But the rising air and warm waters on the tropical Pacific’s east side spawned two of the freakiest, most intense tropical cyclones in recorded history. In October, Hurricane Patricia became the strongest storm measured to date by the National Hurricane Center in the Northeast Pacific, with winds of 215 mph. Then, in February, Winston became the fiercest storm on record in the South Pacific, with winds of 185 mph

In the Northern Hemisphere, 25 category 4 or 5 tropical cyclones, the most intense variety, spun up in 2015, the most on record by far.

While El Niño can be implicated in weather and climate extremes all over the world, it did not deliver in the one place that perhaps needed it the most. It was forecast by many to deliver heavy rainfall in Southern California — mired in a multi-year drought — but the rain really never came.

“Instead of torrential rain in Southern California (and the mudslides that came along with it), the region ended winter with well-below average precipitation,” wrote The Post’s Angela Fritz. “Even worse, California statewide snowpack was just 87 percent of average at its peak. It’s true that this year’s snowfall was a huge improvement over the previous winter, but the amount of water stored in the snow has fallen short of what was hoped for, and even expected, due to a very strong El Niño.”

Here are the types of weather we can expect around the world this year due to El Niño. (World Meteorological Organization/ YouTube)

With El Niño in our rearview mirrors, forecasts now say chances are good that La Niña — its opposite phase — will develop by late this summer or this fall.

The impacts associated with El Niño typically reverse during La Niña. So we might expect the rapid rise in global temperatures to slow. This might allow the corals to partially recover while rains return to Indonesia.

Meanwhile, tropical cyclone activity in the eastern Pacific is likely to slow, but potentially ramp up in the Atlantic. As for rainfall in California, La Niña is associated with drier-than-normal weather — meaning the drought might continue or even get worse.