Agree with the above. Keep it layered, and bear in mind that if you are anywhere along the Hudson or the East River, morning and evening temps are five to ten degrees cooler than elsewhere in the City, due to the high winds. A twinset in a silk cashmere blend (or just a very light cashmere) is great. If you are going to be out late, late at night, you may need a heavier jacket (and maybe even some gloves) depending on how cold you get. I like to wrap a silk scarf around my neck in the morning, then transfer it to the handle of my handbag as it gets warmer during the day. If I need it around my neck again in the evening, it's right there.