The chart shows the time series for the five lowest years of September Arctic sea ice extent.
2020 came in second
This is only the second time in the 40 years we have had satellite monitoring of sea ice that the minimum dropped below 4 million sq kilometers.
In the first week of September, sea ice extent took a sharp downward turn, exceeding the pace of decline for any previous year during that period, and placing the 2020 sea ice minimum firmly as second lowest—after 2012—in the 42-year continuous satellite record. Pulses of warm air from north-central Siberia are responsible for the late downward trend. Sea ice decline has slowed in the past few days, and the annual minimum is imminent.