Year-To-Date Average Sea Ice Extent

With 2018 ending at a 2nd lowest average for the year for Arctic sea ice extent, and with the new year–to–date average at only the 8th lowest on record after the first week of January, we’re now down to the 5th lowest position per February 20th. These are however still early days, and a 51–day average, while much more reliable than a daily figure, is a lot less indicative of where the year is going than, say, a 100–day or 200–day average. This could still go either way!

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.