I can't run in the cold!

We're having a cold snap down in NOLA and it's making me wimp out. It has been in the 30's to low 40's and I haven't talked myself into running in the chill! I'm working a lot of late shifts this week, which in theory gives me plenty of daylight hours to get my runs in. But I can't drag myself out to run in this cold! There are three reasons for this:
1. My knee is very slowly recovering from an injury this Fall, and the cold makes it ache. Very unappealing. As soon as the ache starts I begin to have second thoughts about any form of exercise.
2. I don't own any cold weather running clothes: No running tights, no fuzzy fleece tops, no hats, no gloves. Just T-shirts and shorts. FREEZING.
3. My cozy bathrobe, a library book, and a cup of tea are more enjoyable than running anyway.

I actually did get out for a run on New Year's Day, and it was bitterly cold. We were in Bay St. Louis and the temperature was in the 30's. Worse, I got up very early, so the sun had not risen yet. And worst of all, there was a stiff, icy, relentless wind and the run I chose had zero protection against the wind.
I ran 9 miles in a usually enjoyable loop that goes through the quaint downtown Bay St. Louis, across the Bay Bridge (which has a lovely walking path), along the beach in Waveland, and back across the bridge. However, there are big hills on the bridge and of course you are completely exposed to the elements. The wind was so strong that I actually couldn't stand up straight at the top of the bridge! Then, of course, it got no better once you hit the beach: the wind just screams in over the water. And what was I wearing? Why, a little T-shirt and some stretchy capri things. My skin was rough, raw, and numb by the time I finished and my long hot shower barely thawed me.
So that taught me a lesson. Stay home in the cold until you have a chance to go buy cozy running hats with optional face masks.

What deters you from your run? Is it the cold weather, or a pressing schedule? Something good on TV? Too much work in the house? Aching joints? Fatigue?