The monster has officially arrived.

On Thursday, the US National Oceanic and Atmospheric Administration (NOAA) confirmed that El Niño — the natural warming of the Pacific near the equator — has formed. And it's not just any El Niño. Forecasters give it a 63 per cent chance of ranking among the strongest since records began in 1950.

This is the climate event that scientists have been watching nervously for months. Even before it officially formed, it picked up nicknames like "super" and "Godzilla." Now it's real, and the warnings are blunt.

"El Niño conditions will pour fuel on the fire of a warming world," United Nations Secretary-General António Guterres said in a video message, calling it an "urgent climate warning."

What makes this one different

El Niño happens when warm water deep in the Pacific rises to the surface. That extra heat messes with weather patterns globally. But this time, the ocean was already hotter than normal because of climate change from burning coal, oil and gas.

"It can get dire very quickly," said Clark University climate scientist Abby Frazier.

Meteorologists expect this El Niño to rival — or beat — the 1997 event, which caused billions of dollars in damage from heatwaves, floods, droughts, tornadoes and wildfires.

What it means for Australia

For Australia, the news is grim. El Niño typically brings drought, extreme heat and heightened bushfire risk. The Bureau of Meteorology has already flagged increased fire danger for large parts of the country this spring and summer.

"Instead of scared, we can ask people to be prepared," said Columbia University climate scientist Muhammad Azhar Ehsan.

The global picture

The effects vary wildly depending on where you live:

  • Western South America — where El Niño was first noticed decades ago — can expect heavy rain, floods and an extra warm summer.
  • India faces more intense heatwaves.
  • Northeastern Africa is likely to swing from severe drought to dangerously heavy rains, according to Ehsan.
  • The Middle East, which has been drought-stricken, could actually benefit from extra rainfall.
  • The Atlantic hurricane season may get a break, but Pacific islands like Hawaii are at greater risk.

In the US, El Niño often means a wetter South and a warmer, drier Pacific Northwest. It can actually help American agriculture overall, said NOAA's Jon Gottschalck. But the extra heat drags down economic growth, according to Stanford climate economist Marshall Burke.

"We have pretty clear evidence that the U.S. economy grows more slowly when temps are above normal," Burke said.

The heat is coming

Several climate scientists predict that 2027 will be the hottest year on record because of the lagging effects of this El Niño, which is expected to peak in the northern autumn or winter.

And as the planet keeps warming from fossil fuel pollution, stronger El Niños are likely to become more common, said Frazier and others. But she cautioned it's too early to say if this specific event is part of that trend.

For now, the message from scientists is clear: brace for impact. This El Niño is shaping up to be one for the history books.