I was actually surprised at how close together the numbers were – less than 9% difference.
This is not even taking into account different brands, roof angles, etc.
We are about 10 miles from the coast as the bird flies, and we’ve seen a few days this month where there wasn’t coastal fog first thing in the morning here. I didn’t see much as I looked westward either, so I would imagine there is at least one day this month when coastal fog had minimal impact unless someone lived just a few blocks from the beach.