[muawiyah]

Of course not. There are seasonal differences in dust content ~ typically you have a very long "dry season" and a short "wet season".

Think of the Arctic and Antarctic areas as being rather desert-like and it all makes sense.

[wendy1946]

Of course not.

Wrong answer apparently. Take a look at post 143 above; there's no other plausible explanation other than people counting snowstorms as years.