Comment 4 for bug 743553

I looked up the terms in Wikipedia and noticed that different "Feels like" indices are used around the world.

-"Humidex" used in Canada
http://en.wikipedia.org/wiki/Humidex

- "Wind Chill" index in North America
http://en.wikipedia.org/wiki/Wind_chill

- "Apparent temperature" used in Australia (and in your patch)
http://en.wikipedia.org/wiki/Apparent_temperature
http://www.bom.gov.au/info/thermal_stress/

- "Heat index"
http://en.wikipedia.org/wiki/Heat_index

Felix I tried your patch. Not surprisingly, it shows different feels like than Yahoo.
Generally it shows lower values and I think it is because it should use the dry-bulb temperature instead of the air temperature.

I think it would be more logical to use the "Heat index" as the "Feels like" and have the others optional.
Here is a calculator from NOAA which we can use:
http://www.hpc.ncep.noaa.gov/html/heatindex.shtml

We also have dew point:
http://en.wikipedia.org/wiki/Dew_point
I managed to calculate it based on the first formula and it agrees with Yahoo.