The State of the Climate is a collection of periodic summaries recapping climate-related occurrences on both a global and national scale. The State of the Climate Monthly Overview - Upper Air report describes tropospheric and stratospheric temperatures, with data placed into historical perspective. Temperatures above the Earth's surface are measured within the lower troposphere, middle troposphere, and stratosphere using in-situ balloon-borne instruments (radiosondes) and polar-orbiting satellites. Global Upper Air reports are available monthly from May 2000, with annual summary reports starting in 2001. The report became completely automated (eliminating the narrative section) in 2014.