Humidity Differences Around Humi

[Flynnster]

Hello everyone,
Things have been going well for my little 150 count humidor, but it is full up to the brim. I've always kept my hydrometer near my bead tube because it was it was convenient, but recently I tried putting it down towards the bottom and noticed it's reading about 8% lower down there.

I can't imagine such a fluctuation in such a small humidor. Is this normal?