Hurricane Polo has been downgraded from category 5 to category 4 but remains an extremely powerful storm off Mexico's coast, with sustained wind speeds near 180 mph. Although forecasters do not expect direct landfall, the slow-moving hurricane is projected to bring severe weather and torrential rainfall to south-western Mexico, posing significant risks of life-threatening flooding and mudslides to coastal regions including Jalisco, Colima and Michoacan.

The storm is being sustained by record-breaking ocean temperatures linked to the El Niño climate phenomenon, which is currently the strongest on record. Sea surface temperatures in the central-eastern Pacific reached 3.05°C above average on 19 September, surpassing the previous record of 3.02°C from 2015. Rainfall totals of up to 15 centimetres are forecast, with 20 centimetres possible in some areas, whilst residents have also been warned of large ocean swells and dangerous surf conditions for the coming days.