> Why does the air feel comfortable at the same humidity level in Calgary, Canada but not in Osaka, Japan?
Why is it, for example, that at 27 degrees C in both Calgary, Canada and Osaka, Japan with a relative humidity of 60% one would barely perceive any humidity in the air in Calgary and yet one would feel very uncomforable and "wet" in Osaka?
Meteorologists use "apparent temperature" or "heat index" to quantify the effect of humidity on
the human body, or how how it feels in sultry weather. The apparent temperature is strictly a
function of temperature and relative humidity, so the apparent temperature would be the same in
Osaka, Calgary, or anywhere else for the conditions you describe. Some factors that might
influence your different perception of the heat and humidity in these locations are your
background (because your body is acclimatized to a particular local climate), how
long you are exposed to these conditions (one day is less uncomfortable than the sixth day
of a heat wave), whether the nighttime conditions are as warm or humid as the daytime
(because a cool dry night leaves you less heat-stressed than a warm humid one), and whether
the people around you are complaining of the heat or not (because the power of suggestion is
strong). This combination of physiological and psychological factors vary greatly, so
the "apparent temperature" does not take them into account.