2018 was the 2nd lowest (start of the green graph) calendar year on record for annual average sea ice extent in the Arctic. After 2016, but before 2017. Since New Year we’ve climbed back up to 4th lowest, and per now it even seems likely we’ll leave this chart at the high end during March, by averaging higher than 10 million km² sea ice extent, for the first time since June 2016.
Q: Where’s the data source for this plot?
A: Here: https://ads.nipr.ac.jp/vishop/#/extent
Q: How can anyone make an annual average graph?
A: Easy. Use a computer. Add all the ice for the latest 365 days, divide by that number of days.
Q: Why would I even do that?
A: Let’s say you want to know how much ice we have in 2019 compared to other years.