The Arctic shattered new heat records in the past year, as unusually warm air triggered massive melting of ice and snow and a late fall freeze, US government scientists said Tuesday.

The Arctic's "average annual air temperature over land areas was the highest in the observational record," said the annual Arctic Report Card issued by the US National Oceanic and Atmospheric Administration.

The Arctic's annual air temperature over land was 6.3 degrees Fahrenheit (3.5 degrees Celsius) higher than it was in 1900, said the report, which covers the period from October 2015 to September 2016.