Dew point above 20 °C feels oppressive to most people; below 10 °C feels dry.
Dew point tracks the actual amount of water in the air, which governs how well sweat evaporates. Relative humidity alone misleads — 90% RH on a cold morning is comfortable.
Acclimatisation moves the whole scale: 22 °C dew point is routine in Singapore and floors a visitor from Scotland. And it only describes still air — 24 °C dew point with a breeze and shade is bearable, while 18 °C in direct sun with no air movement is not.
Estimate with the rule, then check it against the calculator that models it properly.
Open Psychrometer →