The report, titled "The Global Climate in 2015-2019," was released to inform the UN secretary-general’s Climate Action Summit, which will be held in New York on Monday.
"Climate change causes and impacts are increasing rather than slowing down," WMO Secretary-General Petteri Taalas warned.
The tell-tale signs — sea level rise, ice loss and extreme weather — all increased during 2015-2019, which is set to become the warmest five years on record.
A 20 percent rise in greenhouse gas levels has driven global temperatures up by 1.1 degrees Celsius (34 degrees Fahrenheit) above the pre-industrial level.
Widespread heatwaves, record-breaking fires, tropical cyclones, floods and drought have led to loss of life and harvest in many countries in these past years.
Ice has been shrinking at an increased pace in the Antarctic and Greenland, becoming the main contributing factor to the rise in sea levels.
"As we have seen this year with tragic effect in the Bahamas and Mozambique, sea level rise and intense tropical storms led to humanitarian and economic catastrophes," Taalas added.
Tropical cyclones, he said, were the cause of the largest economic losses attributed to extreme weather. The 2017 Atlantic hurricane season alone was the most costly on record, with over $125 billion associated with Hurricane Harvey.
