MERRA-2

From variable 3.7
Summary of observation-based historical datasets with specific and/or relative humidity available
reference

source
NASA
data type
Global atmospheric reanalysis
spatial domain
Global
spatial resolution
½° latitude x ⅝° longitude
temporal coverage
1980/01 to present
time step
Hourly; Daily; Monthly
data format
NetCDF
comments
2nd generation reanalysis. Provides 2 m and 10 m specific humidity. Provides also 2 m dew point temperature (information on temperature variables are provided in Near Surface temperature subsection).