The Year–To–Date average extent went from 6th to 4th lowest for sea ice in the Arctic on Thursday, after the YTD graph peaked record early this year. Now the 4 lowest years are also the 4 most recent years.
Q: Where’s the data source for this plot?
A: Here: https://ads.nipr.ac.jp/vishop/#/extent
Q: How can anyone make a year-to-date average graph?
A: Easy. Use a computer. Add all the ice for every day so far this year, divide by the 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.