Feels-Like Temperature Calculator

Different dispatchers: the NWS convention (this tool) uses heat index/wind chill with a neutral gap; AccuWeather's patented RealFeel adds sun angle, cloud cover and precipitation; Environment Canada swaps in humidex; Australia's apparent temperature (Steadman AT) runs one continuous formula including wind AND humidity at all temperatures. Same inputs, different models — disagreements of 3–7° between apps are normal and neither is lying. Check which system an app cites before comparing.

Modeling honesty: in mild conditions a clothed human in shade maintains thermal balance without measurable strain from ordinary humidity or wind — the heat-index regression is only fitted above 80°F and the wind-chill trials only ran at/below 50°F with wind ≥ 3 mph. Extrapolating either outside its fit range produces nonsense (the heat-index polynomial goes wild at 60°F). So the convention reports plain temperature there — accurate, if anticlimactic.

It's the right first number with known blind spots: heat index assumes shade (full sun adds up to 15°F) and a light breeze; wind chill assumes a dry, exposed face — moisture accelerates both directions (wet skin in cold is far worse than the chill number; high sweat in heat is what the index models). Occupational standards use sturdier instruments (WBGT for heat work-rest cycles) when livelihoods and lawsuits attach. For deciding between a run and a treadmill, feels-like is exactly the tool.

Up to 13–15°F equivalent on the heat side: solar gain on skin and clothing adds load the shade-assuming heat index omits, which is why WBGT (the occupational standard) carries an explicit globe-temperature term for radiation. In cold the sun helps less than people hope — a few degrees of radiative relief on a calm sunny day, mostly erased by any wind. Practical rule: in summer, add ~10°F to this tool's answer for sustained full-sun exertion.