The UN urged all countries on Tuesday to bolster early warning systems after confirming the onset of El Niño, warning that the Pacific Ocean-warming phenomenon will bring above-average temperatures “nearly everywhere” and fuel more extreme weather.

A new warning was issued on June 2 about the looming El Niño climate pattern.

"Summer temperatures could certainly be impacted, possibly this year, but more likely next, as the planet heats up," says Professor Bill McGuire, emeritus professor of geophysical and climate hazards ...