It's because you're the same latitude as Namibia, Botswana etc. Even Perth is on the same equivalent (south instead of north) as Cairo or Kuwait.

There's a reason the indigenous Australians stayed dark skinned after 40,000 years - a time frame more than long enough for the Irish to turn red-haired and pale; as a trait it's relatively fast evolving, Europe probably evolved most/all of its variation since the last ice age.