Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

As usual, the minimum was reached during September, and as with other data sets (extent and area), this year's minimum was second lowest on record. PIOMAS bottomed out at 4058 km3 on 14 September, which is 244 km3 lower than 2011 and 385 km3 higher than 2012. In total, 18,432 km3 of sea ice volume was lost, which is the fourth highest amount in the 2007-2019 period. What is interesting to note, is that the three years that lost more volume all started out with a lot more ice than 2019: As can be seen on the PIOMAS Daily Arctic Ice Volume graph, the trend line quickly shot up after the minimum was reached, though 2019 is still second. Overall, September saw an increase of 398 km3, which is the highest increase in the 2007-2019 period (the average is 1 km3). This means that 2012 increased its lead over 2019, and all the other years crept closer.

Here's how the differences with previous years have evolved from last month:

Wipneus' version of the PIOMAS graph shows how this year deviated from 2012 quite quickly:

Given these developments it is only logical that the anomaly trend line on the PIOMAS volume anomaly graph has shot up some more, almost reaching the linear trend:

This is where things get interesting. We've seen that PIOMAS has gone up steeply since the minimum. JAXA extent, however, has done so more slowly. This means that the volume is spread out over a relatively smaller ice pack, and so average thickness goes up. When you divide PIOMAS volume by JAXA extent (a crude method to calculate average thickness), this is how it looks: 2019 average thickness was among the lowest for a while, but shot up recently. Interestingly, the Polar Science Centre average thickness graph shows a different picture, with 2019 actually going lowest, but that's probably because the trend line stops mid-month:

It will be interesting to see what happens in coming weeks, given that the trend line has gone up very slowly on the JAXA graph and is lowest on record again. Yes, even lower than 2012. Melting momentum may not have delivered new record low minimums, but all that heat that was built up on the periphery hasn't disappeared just like that.The question now is whether we will see a similar situation to the one we witnessed in 2016, with a long streak of ultra-low daily records, making the global sea ice extent graph go viral (also depending on Antarctic sea ice, of course). That winter ended with a record low PIOMAS maximum.

It's still early days for that kind of speculation. In the meantime, though, September Arctic-wide temperatures were 2nd highest on record. That's the 6th month in a row that ended up in the top 3, and October could very well achieve the same:

And so we watch.