Winds primarily cause the apparent sea ice ‚breakup‘ in late spring through the widening of persistent polynyas and shore leads. This year the development of critical open water areas in Canada (which are important feeding areas for polar bears) is on track with previous years in most areas, although there is a lot of year-to-year variability.

Several prominent polynas also opened up along the Russian coast and Northeast Greenland: see the entire Arctic condition at 7 June 2021 below, courtesy NSIDC:

Below are sea ice charts for Canada from 6 June 2021 compared to others back to 2013 at about the same date from the Canadian Ice Service.

2021:

Compare the above to previous years at about the same time.

2020

2019

2018

2017

2016

2015

2014 (17 June is the closest I have in my archive for 2014)

2013

via polarbearscience

June 8, 2021