A heat wave pulsating through the Arctic helped push Alaska to its warmest month ever recorded in July, with the state’s vast coastline left completely barren of sea ice.

Alaska’s average temperature in July was a record 58.1 degrees F (14.5 degrees C), nearly 1 degree F above the previous monthly high set in July 2004, according to the National Oceanic and Atmospheric Administration. Cities and towns across the vast U.S. state, such as Anchorage, Utqiaġvik (formerly known as Barrow), and Kodiak all had their warmest month in 125 years of record-keeping.

This heat, 5.4 degrees F warmer than the long-term average for July, helped spur wildfires that shrouded much of Alaska in a pall of smoke and has now resulted in a remarkable melting away of shoreline ice.

There is now no sea ice within 150 miles of Alaskan shores, according to an analysis by the National Weather Service. The pace of ice loss is “unprecedented” in 40 years of satellite records, scientists said, with the Bering Sea, which separates Alaska from Russia, left completely ice-free.

The record-breaking warmth in Alaska is part of a broader heat wave that has swept the northern latitudes, with Greenland shedding a record 12.5 gigatons of ice into the ocean in a single day, Norway experiencing its joint hottest day ever, and forest fires in Siberia tearing through an area as large as Belgium.

Scientists warned that the extreme conditions are consistent with the most pessimistic scenario where countries do little to constrain global heating by cutting planet-warming gases from cars, trucks, and power generation.