My newspaper publishes Accuweather Real Feel temperatures. That means if the thermometer says 85F, the Real Feel temperature is what it really feels like, taking into account a bunch of other factors (humidity, sun angle, wind, etc.).
So my question is if the temperature is 85F, what are the conditions that will make the Real Feel 85F? What humidity do they consider “normal”? What wind speed makes it feel normal–zero?
I also wonder if this is adjusted for locale. For instance, you will rarely get low humidity in Miami, so 85F with high humidity should feel like 85F.
The baseline is surely the dry bulb temperature which is the actual temperature of the air and nothing else. Humidity and wind aren’t measured. Dry bulb is simply a regular thermometer reading, but to be accurate it has to be shielded from radiation and moisture.
Heat index and wind chill are both calculations to estimate how humans will perceive the temperature. Real Feel is some sort of more complicated version of these. Temperature is reported as the dry bulb temp, so any time you hear the temperature is X, unless they mention the heat index or wind chill or Real Feel or whatever, they’re talking dry bulb air temperature, the actual thermodynamic temperature of the air molecules around you. In Miami, if the temp is 85F, that means the air is really 85F.
The formula is arbitrary, because it depends on what a lot of different people supposedly feel. People are notoriously bad at estimating the temperature, so there is a very nebulous concept of “feels like”. Canada and the US do not use the same formula, and the US Heat Index is not the same as the Canadian Humidex. Meteorologists in the two countries have held joint talks to try to agree on the same formula, but failed to reach a consensus so they remain different.
The body is cooled by the evaporation of perspiration on the skin. If there is too much moisture already in the air, there is less evaporation, so less cooling.
Personally, I just cut through all the balogna, and I look at the Dewpoint. Regardless of the summer temperature, I always feel hot if the viewpoint is over 75, and I feel comfortable if it is below 70. If the temperature is over 100 and the dewppoint is about 71, I walk to the supermarket, and it’s fine. If it’s 82 and the dewpopint is 76, I stay in and plan my walk for a more refreshing day.
At around 8 am, there is often a temperature of 80 and a dewpoint of 77, and it’s brutal.
The question is: If the indicated air temperature (which I now know to be the “dry bulb” temperature, thank you :)) is 85F, what conditions must exist for the Real Feel temperature to be 85F?
That is, what conditions do people perceive as “normal” humidity, wind, and whatever else goes into the equation?