AccuWeather has an interesting system called RealFeel. For example, today is 22ºF, but when you step outside, you can’t help scream “Shit, it’s cold!”. Accourding to the AccuWeather’s RealFeel system (which I assume takes into account more than just humidity, like wind), it feels like 10ºF. What it does not take into account is if you forgot your hat, scarf, or gloves (then you are lost, even if you wear UniQlo’s HeatTech undies) 😉