Hurricane Polo downgraded but remains 'very powerful' off coast of Mexico

23 September 2026, 03: 54 BST. Updated 11 minutes ago.

Key points

• Hurricane Polo, a sizeable storm off the coast of Mexico, has been downgraded to category 4 but remains "very powerful", the US National Hurricane Center stated.
• Rainfall totals of up to 6in (15cm) are forecast, with 8in feasible in some areas.
• Sheinbaum highlighted the states of Jalisco, Colima and Michoacan as being at risk.
• It was previously a category 5 storm – the highest level on the scale – but was downgraded to category 4 on Wednesday morning.
• Trade winds that typically blow from east to west throughout the Pacific Ocean can weaken or even reverse, allowing warm water to spread eastwards.

Though was not projected to produce landfall, the Pacific hurricane, one of the strongest of the season, was projected to head towards the coast of south-western Mexico, bringing intense wind and rain.

Meanwhile, a Hurricane Hunter aircraft, operated by the US National Oceanic and Atmospheric Administration (Noaa), flew into the storm on Tuesday and recorded sustained wind speeds near 180 mph (285 km/h), with stronger gusts.

In practice, the slow-moving storm is being fuelled by extremely warm waters caused by the El Niño climate phenomenon.

As it gradually drifts northwest, Polo will drive torrential rainfall in parts of Mexico's south-west coast, and "may produce life-threatening flooding and mudslides, especially in areas of steep terrain, " the forecaster stated.

Rainfall totals of up to 6in (15cm) are forecast, with 8in feasible in some areas. Residents have additionally been cautioned of sizeable ocean swells and life-threatening surf conditions for the next few days.

"So far, the information we have is that (Polo) will not make a direct landfall on the coast, " Mexico's President Claudia Sheinbaum remarked on Tuesday, but she cautioned residents along the Pacific coast to be vigilant. Sheinbaum highlighted the states of Jalisco, Colima and Michoacan as being at risk.

Since of what NOAA called a "very conducive" environment of extremely warm ocean waters feeding the storm, data from the Hurricane Hunter aircraft indicated that Polo could still strengthen.

Scientists monitoring the ocean temperatures say the current El Niño climate phenomenon is now the strongest on record.

Daily sea surface temperatures in a key region of the central-eastern Pacific were 3.05C above average on 19 September – exceeding the previous record of 3.02C set during the particularly robust El Niño of 2015.

Some longer-term measures of El Niño have not yet hit record levels but this is projected to change, with the peak not anticipated until afterwards this year.

Warmer ocean waters mean storms can pick up more energy, leading to higher wind speeds.

El Niño is a naturally-occurring pattern. It happens regarding every two to seven years and tends to last for around a year.

Heat is then published from the ocean into the atmosphere which can boost global temperatures and drive changes in weather patterns worldwide.

In short, hurricane Polo downgraded but remains ' very powerful' off coast of Mexico is the central thread here, and readers can expect follow-up reporting as the picture becomes clearer.