Room temperature & often past their sell by date! I just give 'em a sniff when I crack them usually.
However, if they're very much past the date then I do the 'egg in water' test...put the egg into a cup of water, if it sinks - it's ok! If it floats, it's rotten. (Rotten builds up extra gas inside the shell, I believe, which accounts for it floating.)
I wasn't sure whether to really believe that or not, but I had a floater awhile back...heeee! So it's true!

We sometimes have them awhile because I'm the only egg eater in the household & unless we're baking - well they might sit a bit longer.
Our room temperature is usually on the cool side - if it were hotter, then I'd probably refrigerate them.