What is “Normal” Temperature?


Every 10 years, the National Centers for Environmental Information releases statistics on “normal” weather for the US. This data is used in a variety of ways, for example to say that today is warmer or colder than normal. The problem with this is that it does not capture long term trends, comparing the past decade to the prior one is not as useful as looking at the past 100 years. The chart above does just that. It compares the 30 years from 1991-2020 to the entire 20th century. There’s no doubt about it, we’re heating up. If we looked at just the past 10 years compared to the prior 100 it would look even worse.

Of course, this same problem exists when looking at fish counts. Everyone talks about current numbers relative to the past 10 to 20 years. What we should really be looking at is current population estimates in relation to the past 100+ years. When you do that it is downright depressing.