National Oceanic and Atmospheric Administration
https://psl.noaa.gov/data/gridded/data.20thC_ReanV2.html

National Oceanic and Atmospheric Administration
https://psl.noaa.gov/data/gridded/data.godas.html

National Oceanic and Atmospheric Administration
https://psl.noaa.gov/data/gridded/data.ncep.reanalysis.html