Visual graphics: Hurricane Polo turns Category 5. Why the world is watching El Niño

Hurricane Polo has intensified into a Category 5 storm off Mexico’s southwestern Pacific coast, becoming one of the most powerful hurricanes to form in the region in recent decades.

The US National Hurricane Center (NHC) said early Wednesday that Polo was nearly stationary about 325 km south of Zihuatanejo, Mexico, with maximum sustained winds of 270 kmph and a minimum central pressure of 905 millibars. The storm was expected to turn sharply northwest before moving west-northwest over the following days.

The NHC had earlier described Polo’s rapid intensification as “truly remarkable”. Its winds increased by about 90 knots over 24 hours as the storm strengthened rapidly.

The storm’s core was expected to remain offshore, but its slow movement has kept Mexico’s Pacific coast under threat. The NHC warned of tropical-storm conditions and 4 to 8 inches of rain, with isolated totals up to 12 inches, across parts of Guerrero and Michoacán. Such rainfall could trigger life-threatening flooding and mudslides, particularly in mountainous areas.

Hurricane #Polo is a Category 5 monster, with winds of 285 km/h (180 mph), and could reach 295 km/h (185 mph) soon. Polo is forecast to skim along the southwestern coast of Mexico over the next few days, narrowly avoiding a catastrophic landfall. pic.twitter.com/bjfiE5ZU59 — Zoom Earth (@zoom_earth) September 22, 2026

Mexican authorities temporarily suspended classes in some coastal areas and closed ports in Guerrero and Michoacán as a precaution, news agency Associated Press reported.

Why did Polo intensify so quickly?

One factor scientists are examining is El Niño, the naturally occurring climate pattern marked by unusually warm surface waters in the central and eastern tropical Pacific. This year’s El Niño is unusually strong and is expected to strengthen further.

💨 Max Sustained Winds 165 mph

⏲️

905 mb

Min Central Pressure

📍

200 mi

South of Zihuatanejo

🌧️ Forecast Rainfall Impact

4–8 in

Guerrero & Michoacán

Up to 12 in

Isolated Max Rain

The World Meteorological Organization said in its September update that there is an almost 100 per cent likelihood that El Niño will persist through February 2027. It expects the event to intensify to a very strong level in the coming months, with its peak towards the end of 2026.

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The WMO said sea-surface temperatures in the central-eastern equatorial Pacific were already exceptionally high. The Niño 3.4 index, one of the key measures used to monitor El Niño, had reached weekly values of roughly 2.2°C to 2.6°C above average between late July and mid-August. In some areas, subsurface ocean temperatures were more than 8°C above average.

AP quoted Philip Klotzbach, a research scientist at Colorado State University, as saying El Niño had provided favourable conditions for Polo’s rapid intensification, with warmer Pacific waters and wind patterns creating many of the ingredients needed for a powerful storm.

But El Niño should not be presented as the sole cause of Polo. Tropical cyclones depend on multiple oceanic and atmospheric conditions, and the precise contribution of individual factors to one storm can be difficult to establish.

The Guardian, citing meteorologists, similarly linked Polo’s rapid strengthening to the unusually strong El Niño and noted that the Pacific and Atlantic basins are responding very differently to the phenomenon.

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One El Niño, two very different hurricane seasons

Polo’s development is particularly important because the Atlantic hurricane season has had the opposite experience. According to AP, no Atlantic hurricane had formed by Tuesday, making 2026 the slowest start to an Atlantic hurricane season on record. El Niño can increase wind shear over the Atlantic, making it harder for tropical systems to strengthen.

In the Pacific, however, warmer waters and atmospheric conditions associated with El Niño can favour tropical cyclone development.

The Guardian reported that the lack of an Atlantic hurricane by September 21 was unprecedented in 112 years of records.

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El Niño

Warmer Pacific

Hurricane Polo

Category 5

South Asia

Heat + Rainfall

Changes

SE Asia & Australia

Severe Drought Risk

Southern Africa

Heat + Food

Insecurity

Atlantic Ocean

Stronger Wind Shear

(Hurricanes Suppressed)

Latin America

Rainfall Extremes

(Floods & Drought)

Source: WMO El Niño/La Niña Update, September 2026

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But Polo is only one part of El Niño story

The bigger concern for scientists is what the unusually strong El Niño could mean for global temperatures, rainfall, drought and food and water security.

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The WMO says a very strong El Niño can significantly alter rainfall and temperature patterns across many regions, increasing the likelihood of extreme weather. It cautions, however, that the strength of El Niño alone does not determine how severe the effects will be in any individual country. Other climate drivers, including conditions in the Indian and Atlantic oceans, can modify its impact.

For September-November 2026, WMO forecasts show an increased likelihood of above-normal temperatures across almost all land areas, along with significant shifts in rainfall patterns.

That means the consequences of this El Niño could stretch far beyond tropical storms.

Heat could become the biggest threat

A new study from the Climate Impact Lab, a research group affiliated with the University of Chicago, has put a stark number on the potential human cost.

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The researchers estimate that the current El Niño could lead to 451,000 additional heat-related deaths globally. The study covers the El Niño period beginning in June 2026, with its forward-looking forecast extending through February 2027.

The Indian Express, citing the study, earlier reported that India could see about 15,800 additional heat-related deaths between September 2026 and February 2027, compared with a normal year. The study estimates that global land temperatures could be about 1.2°C above normal, with 44% more extremely hot days than in a typical year.

The researchers’ projections put the heaviest burden on poorer and already-hot regions.

The study estimates:

• 66,800 additional heat deaths in the Sahel
• 31,400 in Nigeria
• 17,500 in Sudan
• 19,300 in Indonesia
• 19,400 across the Philippines, Vietnam, Thailand and Cambodia
• 15,800 in India
• 13,300 in Brazil.

451,000

Projected additional heat-related deaths globally

Worst-Hit Regions

66,800

The Sahel

19,300

Indonesia

15,800

India

13,300

Brazil

44%

Projected increase in extremely hot days.

What does this mean for India?

The southwest monsoon has already begun withdrawing from parts of northwestern India, while 43% of the country’s geographical area remained rain-deficient as of September 19, according to the IMD. Cumulative rainfall was about 15% below normal.

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Climate · El Niño 2026–27

Why India is watchingthis El Niño very closely

Very strong

WMO classification, September 2026

∼100%

WMO probability it persists through Feb 2027

+2.6°C

Peak Ninño 3.4 anomaly, mid-August (above normal)

India’s watch listThe numbersClimate context

What India is tracking

Six things India is tracking

⛆

Rainfall

IMD forecasts 90% of the long-period average — the first below-normal projection in three years.

Source: IMD

☀

Heat

WMO forecasts above-normal temperatures across almost all land areas, Sep–Nov 2026. It warns 2027 could exceed 2024 — the hottest year on record.

Source: WMO

☔

Water

Below-normal monsoon threatens reservoirs and irrigation. Borewells in some regions now need 180+ feet where 40 once sufficed.

Source: Reported; IMD

🌿

Agriculture

Around 60% of India’s farmers rely on monsoon rainfall. IMD warns El Niño could cut both kharif and rabi yields, lifting food prices.

Source: Down to Earth; IMD

🌊

Indian Ocean Dipole

A positive IOD is developing (+0.9°C forecast, SON 2026). It can partially offset El Niño’s rainfall suppression — but its 2026 effect has been limited.

Source: WMO Sep 2026

⌛

Duration — through February 2027

WMO gives near-100% odds the event persists to February 2027 — the most unequivocal forecast in its history. INCOIS: 85–98% through March 2027.

Source: WMO; INCOIS

The key numbers

Six figures

+2.6°C

Niño 3.4 SST anomaly, mid-Aug 2026

+8°C

Subsurface ocean temp anomaly, Jul–Aug 2026

~100%

WMO odds of persistence to Feb 2027

90%

IMD monsoon forecast (% LPA)

60%

IMD odds of deficient monsoon

+0.9°C

Positive IOD forecast, SON 2026

Monsoon vs long-period average

Normal (100% LPA)

IMD forecast: 90%

WMO odds: persists to Feb 2027

Certainty threshold

∼100%

IMD odds: deficient season

Historical base rate: 16%

This year: 60%

How to read this

El Niño ≠ climate change

The WMO is explicit

El Niño is a natural climate phenomenon, not caused by climate change. The WMO states this directly and explicitly.

WMO, September 3, 2026

The complication

2024 was the hottest year on record at 1.55°C above pre-industrial levels. Pacific subsurface anomalies hit +8°C this August. The phenomenon is natural; the warmer baseline it sits on is not.

WMO; Down to Earth

The modelling claim (attributed)

Climate Impact Lab modelling suggests the heat from this El Niño resembles conditions projected for roughly 20 years from now. One research group’s model — not a WMO finding.

Climate Impact Lab (modelling)

Sources: WMO, September 3, 2026 (primary); IMD; INCOIS; NOAA; Down to Earth.

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The rainfall deficit has been particularly significant in several states, including Meghalaya, Andhra Pradesh, Arunachal Pradesh, Bihar, Kerala and Karnataka. At the same time, some eastern and central parts of the country have continued to receive heavy rain.

This matters because the impact of a strengthening El Niño is not simply a question of whether India gets a weak monsoon.

The interaction between El Niño and other oceanic conditions, including the Indian Ocean Dipole, can change the eventual weather pattern.

The WMO expects a positive Indian Ocean Dipole to develop during September-November, while cautioning that other climate drivers can reinforce, weaken or alter the typical effects of El Niño.

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What happens next?

For Mexico, the immediate concern remains Polo’s slow movement and the risk of heavy rainfall, flooding, mudslides and dangerous coastal conditions. The NHC’s latest advisory keeps Polo stationary offshore with 165 mph winds, although hurricane intensity can fluctuate.

The WMO expects El Niño to strengthen further before reaching peak intensity towards the end of 2026 and to persist through February 2027. It warns that the event could bring major changes in rainfall and temperature patterns, with increased risks of drought, flooding and extreme heat.

(With inputs from agencies)