Auto trans problem when cold 99 wrangler

I have a 1999 wrangler with an automatic trans that seems to have problems shifting only when the vehicle is cold. I have changed the trans fluid, and that didn't help. As soon as the weather changes and is warm, the problem goes away until fall. Any ideas????

If you've got high mileage, you might have some gunk in the valve body (the thing you can see when you take off the pan). A good cleaning may take care of it (and can't hurt). You may also want to look into a shift kit for it, as there are springs that weaken over time. I had an auto trans vehicle once that didn't want to shift 1-2 and 2-1, put in a shift kit and it shifted like a dream after than.