where Ein = energy absorbed by the surface in J / s, S = the solar irradiance in W / m2, θ = angle of the sun from the zenith, α = absorptivity of the surface at the solar radiation wavelengths. (scienceofdoom.com)
Note 2 — Emissivity = Absorptivity at a particular wavelength (and direction for «non-diffuse» surfaces). (scienceofdoom.com)
Therefore the temperature of a body in sunlight may be much higher (like 200C higher) or much lower (like 100C lower) than that of a black or gray body that has equal absorptivity for SW and LW. (judithcurry.com)