Last week, I went to start my car in the morning and it wouldn't immediately start. After cursing a bit, I held the key for ~10 seconds and it fired up. I drove home (30 min drive), turned it off for 15min, and started it again by holding the key for longer than normal. This was the first really cold night of Fall.
After that, it started normally until this afternoon. My car will not currently start, and holding the key produces a constant clicking. The battery seems to be fine; at least everything lights up. I tried reseating the battery cables and tapping the starter, but the problem persists.
2 years ago (almost exactly), I replaced the battery (didn't fix it) and the starter (fixed it). This problem seems to be brought on by cold weather. I'm wondering if something is causing my starter to fail prematurely, or other explanations to what's going on.