Global temperature records start around 1880 because observations did not sufficiently cover enough of the planet prior to that time. The line plot above shows yearly temperature anomalies from 1880 to 2020 as recorded by NASA, NOAA, the Berkeley Earth research group, the Met Office Hadley Centre (United Kingdom), and the Cowtan and Way analysis. Though there are minor variations from year to year, all five records show peaks and valleys in sync with each other. All show rapid warming in the past few decades, and all show the last decade as the warmest.