I had problems with my tools rusting in my hangar. I used silica gel dehumidifiers which worked but needed 'recharging' every three months or so. I switched to putting Bullfrog rust blocker strips in the drawers of my toolbox. I haven't had a problem since. I just have to remember to change them every year.
I find a huge difference if I leave the tools out (they rust) versus keeping them in a closed toolbox (they don't). I try to keep them put away, especially during those condensing times that Dan mentions.