I agree with some of the above posters. It's hard to pin a number on base weight without an exact definition. If it is the weight of your pack minus consumables, what about clothing worn, hiking poles, and the contents of your pockets? That can add up to quite a bit. "Skin out" weight is the term I like to use. It includes all of the above and I feel that it paints a much more realistic picture.

My base weight is all over the board depending on the time of year, daily mileage, presence/absence of snow, group size (shared equipment) expected temps, duration of the trip and, most importantly, the level of comfort/convenience I desire. I can safely say that it has never been the same from trip to trip.