I've had a quick go at a Makeover Monday
You can see my attempt at analysing the 9 April 2018: Arctic sea ice extent dataset. (The link is to an nbviewer version of the page.)
Here's a visualisation of the change in sea ice extent, against the median values for each month. As you can see, 2012 was a bad year.
Code is available on Github.
Data from US National Snow & Ice data centre via Makeover Monday.