Yes, can be. Here is an example spectra of the sun mid-day partly cloudy northeastern US late spring.
In this sample the PAR (400-700nm) measured as 1580 umol / m^2 s as captured by a spectrophotometer:
The solar irradiation will vary by location, environmental conditions, calendar date, and time of day.
For instance, here is what the DLI looks like based on latitude and day-year (estimated daily light received in Mols:
And how the amount of irradiation varies based on time of year, this is Ecuador (graph is rotated clockwise):
And, here is Sydney:
etc…