If you’ve ever wondered how the global average temperature is calculated, especially considering that we don’t have surface temperature observations at many point on the globe (especially the poles), then this article is for you. The Climate Lab Book blog from the U. K., provides an excellent scientific overview of how a global mean temperature is calculated and how it has changed over time as the number of observations has changed. There’s a video included as well to show how the changes have occurred over time. You can read it at https://www.climate-lab-book.ac.uk/2018/what-does-mean-actually-mean/.