Arctic sea ice has likely reached its maximum extent for the year, at 14.62 million square kilometres (5.64 million square miles) on March 6, according to scientists at the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder. The 2023 maximum is the fifth lowest in the 45-year satellite record.

NSIDC scientists stress that the Arctic sea ice extent number is preliminary—continued winter conditions could still push the ice extent higher.

We spoke to our Chief Science Officer, Professor Julienne Stroeve about this year’s maximum and what this might mean for the summer sea ice this year. Watch the video below.

Why is sea ice important? Arctic sea ice is an indicator of climate stability. Today, there is about 40% less sea ice coverage at the end of the melt season than existed in the 1980s. The ice area shrank by almost half the size of the entire European Union. What was left was smaller than at any time in at least 1,000 years. But sea ice loss also worsens warming. White ice cover reflects much of the sun’s energy back out to space. But as ice disappears, the dark ocean is exposed, absorbs more of the sun’s energy, and warms, helping to melt more snow and ice. Estimates suggest that the loss of Arctic sea ice together with reductions in snow cover over the boreal land areas will exacerbate global warming by 25 – 40%. CLICK TO SEE THE DATA.

The NSIDC’s formal announcement will be at the beginning of April with full analysis of the possible causes behind this year’s ice conditions, interesting aspects of the growth season, the set up going into the summer melt season, and graphics comparing this year to the long-term record. Read the NSIDC Arctic Sea Ice News & Analysis page for more details and images.