Alaska is set to finish 2019 with a record average high temperature after a year of extremes ranging from a sweltering summer and rampant wildfires to vanishing sea ice and winter rains where heavy snows were once the norm.

Wildlife also suffered from the state's chaotic weather, with mass die-offs of seabirds and marine mammals struggling to cope with ecological upheaval.

The turmoil is part of a rapid warming pattern in which Alaska — at the leading edge of climate change due to its proximity to the Arctic — is heating at twice the rate of the planet as a whole, researchers say.