I live in the DC metro area and we recently had snow that lasted all day (none stuck to the roads, booo). But I didnt understand that it was still snowing at well above freezing. I have a digital thermometer outside of my window and it read ~41 degrees F at its highest and never dropped below 32 until around midnight after the snow passed. The %error is only rated at +/- 2 degrees F but will still be above freezing. If I remember right, humidity on weather.com was ~65% as well. Ive seen this before and even rain when it was in the high 20's. We must have been under a low pressure system which brought all the moisture. Does atm pressure matter that greatly? What causes it to snow above freezing or rain below? I cant think of anything else that I know of that could cause this. Just curious but any help is appreciated.