Does coffee dry out in open air?

Situation: to save time in the morning, I put a couple of spoonfuls of coffee into the coffeemaker the night before, and fill the water tank. So the next morning I just need to flip the little red switch and the coffee will be ready.

But in doing so, I am exposing the coffee to air for a 6–7 hour period. Not much time, true, but certainly not the same as being in the tightly sealed can (or silver lined bag) where it was before.

Am I doing perceptible damage to the taste of the coffee in letting it oxidize for 6–7 hours?

(I’m discounting the potential danger that ants or coffee-eating insects could crawl into the coffee maker – while potentially true, it’s not a major concern.)