I'm thinking more of an Irradiance map where the value is the current W/m^2 at a specific location, which would take into account latitude and time of year (to get the angle of the Earth relative to the sun), along with other factors like clouds, altitude.

e.g. https://www.nrel.gov/gis/images/solar/solar_ghi_2018_usa_sca... but on the daily.