If the temperatures are variating lately the rough idling could be caused by condensation within the fuel lines from it being hot/cold, hot/cold. Mine ran rough a couple months back while I was driving uptown. Even stalled once when I went to stick it in reverse. I assumed it was due to condensation. So I started it back up 5 minutes after it happened and it's been fine ever since. If it just happens this one time I wouldn't be overly concerned about it, probably condensation in the fuel lines as I mentioned. If it happens frequently I would probably investigate it further.
