2023 is "virtually certain" to be the warmest in 125-thousand years.
EU scientists gave the warning after the hottest October in that period.
Scientists also say October's temperature record was broken by 0.4 degrees Celsius.
The average surface air temperature last month globally was 1.7 degrees above the pre-industrial age.
There's a target of limiting global warming to 1.5 degrees above that target.
Experts add there's an urgent need for action to stop planet-warming emissions.
This year has seen countries worldwide hit with severe heatwaves, floods and wildfires.
While Met Eireann say throughout October nine weather stations in Ireland had record high temperatures for October.
Some places also had double the usual amount of rain.
Flooding caused major issues in parts of Cork in the last few weeks.Risks
Environment journalist John Gibbons doesn't believe the general public understands the risks:
"I think we've become a little blind to it," he said.
Continuing, John says that's a "dangerous idea," that people are "beginning to get used" to extreme weather events.
"We need to be alarmed by the trends in our weather system."
John says we should be alarmed by them and we should not be complacent.
"But I don't yet believe the general public understands how much risk is posed to our property and indeed to our own welfare."
