Coolant Question

I've noticed my coolant overflow tank next to the windshield washer fluid is bone dry. When I first bought the vehicle it was about 1/4 way filled. Now at 10k miles later it's dry. I will be adding more fluid tomorrow but is this a concern? Also, does anyone's temperature gauge fluctuate or does it stay consistently at the half way mark. I've noticed mine may go just a tad over 1/2 way then creep back down to normal. Thanks

Not trying to be stupid, but are you looking at the overflow tank at the same time? I mean with engine hot or cold. Will make a difference in the level you see.

Sorry about that! I just looked at it and the engine is hot but I think I remember seeing it at the same level when cold.