May 2019 Global Temperature Update
May 2019 was the 3rd warmest May in the 140-year instrumental record at +0.87°C relative to 1951-1980 (2016 was +0.94°C; 2017 was +0.89°C). Most of U.S. was cool relative to 1951-1980, especially compared to the rest of the world. So far 2019 is the 3rd warmest year, but residual effects of this year’s weak El Niño are likely to make 2019 the 2nd warmest year. The 5-month mean is +0.98°C, which is +1.25°C relative to 1880-1920, i.e., relative to our best estimate of preindustrial temperature.
Beginning this month the temperature analyses of both NOAA and NASA Goddard Institute for Space Studies switch to use of version 4 of the Global Historical Climatology Network (GHCN). The effect of the switch on global temperature relative to version 3 is shown below. Version 4 provides an expanded set of station temperature records and more comprehensive uncertainties for the calculation of station and regional temperature trends. (https://www.ncdc.noaa.gov/data-access/land-based-station-data/land-based-datasets/global-historical-climatology-network-monthly-version-4)
A PDF of this Temperature Update is available here.