I have some pretty hot places to be flying to in late July and early August.

I will be flying TLV-JFK and while the plane is apt to be chilly (and possibly the airport), I am going to want to go outside for a smoke or two during my 4 hour connection to SEA.

After SEA, I will be flying to LAS. From LAS, to ATL, and a few days later ATL-JFK-TLV.

In all these places, except perhaps SEA, I do not want to be wearing long pants or a long sleeve shirt. In the planes, I prefer dressing more warmly. My plan is to wear shorts and a t-shirt outside, but in the airports and on the planes, to cover them with track suits.

Can I wear these through the TSA lines or am I going to find that they are considered outter garments and must be removed?

If the track suit top looks like a jacket or is bulky, you'll probably be asked to take it off. If you wanted to argue, you could probably claim that's your outfit and it's not a jacket (and what you have under it is an undershirt) but I'm not sure I'd see the point if you can easily remove the top of the track suit.

I wouldn't expect an issue with the pants at all.

Agreed as to pretty much no issue with the pants but if you absolutely want to keep them on, after you deplane, hit the restroom and remove the shorts as if you "win a patdown" on your re-entry, the TSO will probably feel the shorts under the track suit pants. As to the undershirt/t-shirt, you could do the same thing and remove it thus guaranteeing that you keep the track suit jacket on as if you are asked to remove it, simply tell the TSO that you have nothing on underneath it (and if need be, unzip a little bit in case they are "a tad dense" )