Hi. My DD is always cold and had one of those North Face fleece (thin one) sweaters with her all the time. Once or twice it was chilly at night -- nothing that a light jacket wouldn't fix. But we were moving around alot -- if you are going to sit for an hour or two to watch the parade & fireworks, I would definitely bring a jacket. It was pleasantly warm, but not hot or humid while we were there. Perfect for us, since we run around alot and the heat and humidity really slow us down. Weird thing -- when we left home it was 60 degrees and rainy. It's supposed to be 90 today! Really unusual for us, especially since it's warmer than Florida!