September 11, 2025: (Eight days since the last post) the Arctic sea ice has experienced a very small increase rate for this week of 0.09% (last week’s decrease rate was 2.95%), from the level on 09/03/2025 of 4.667 M km² to 4.671 M km² for this week.  The sea ice extent for 2025 to date has now dropped one spot to 11th place for the lowest sea ice extent for this day of the year as noted below when the lowest sea ice extent was at 3.416 M km² on 09/11/2012.  So, it looks like we are right on the precipice of the change in sea ice seasonality from the decrease season to the increase season; next week’s data should help us with that.  Since last week, sea ice has been oscillating between loss and gain a total of four times, but the last three days have all been trending up.

Ranking of lowest sea ice extent for the day of the post, values in M km² :

2012    3.416
2020    3.849
2007    4.215
2016    4.238
2024    4.250
2023    4.258
2019    4.319
2011    4.346
2015    4.471
2008    4.577
2025    4.671

The negative sea ice anomaly this week was lower than the anomaly of -0.90148 M km² on 09/03/2025 to a lesser negative anomaly of -0.74646  M km² on 09/11/2025, and so less anomalously negative for this time of year.