Thursday, September 16, 2021

Average Compared to What?

The average temperatures — "normal" temperatures — we hear about are a moving target. NOAA and other national weather institutions update what's considered normal every 10 years, based on the previous 30 years' temperatures. Normal is not a permanent thing.

These two images, shared on Twitter by Scottish meteorologist Scott Duncan, make that divergence of reality in temperature data visually obvious:

That's summer 2021 compared to the last three summers. 

When you look at that graphic, it's easy to think, Well, it was hotter this summer in a lot of places, but there were places where it was cooler, too.

But then you see this graphic, which compares summer 2021 to an average summer between 1951–1980:

And you realize it wasn't cooler much of anywhere except the middle of Antarctica, and even the rest of Antarctica was a lot hotter.

Those graphics put our current temperatures more in perspective. I'd say "red alert," but it seems unncessary.


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