In summer, in the Northern Hemisphere, when the sun is 10 degrees above the horizon, the light intensity could be 12,000 Lux. In December in the northern hemisphere, the light intensity when the sun is at 10 degrees above the horizon could be as low as 500 lux. This is over a 5 stop difference.
I was raised right on the Equator and at about 3,000 meters.
Sunny 16 was more or less true, but sunny 22 was closer to the truth. Going to the beach (altitude =0) gave about 1/2-1 stop difference.
Now I live in the USA (35 N) and I've found that Sunny 11 is closer.
Other thing that amazes me is color temperature, In Quito and surroundings we had to use a 1B filter to get the film to render the colors right, otherwise everything lookled awfully bluish.
For ptints it was no problem, since the lab I used down there had their mahcines calibrated for our conditions, but for slides was a pain! Talk about saturated blues and greens!
Here the color temperature is different, everything looks less blue.
Near big water surfcases the light can be completely different, we have quite a lot of water in Holland and it always strikes me that the clouds above water look different than the clouds above land. It also makes a difference on wich side od the water you are.
Above that colours at sunrise and sunset seems to different in other parts of the year never really understood that. The sun can be deep red in spring while it's more yellow orrange in the fall....