Heat Index Calculator
Calculate the feels-like heat index based on temperature and humidity.
Google Ad (Top)
Heat Index Calculator
Heat Index Calculator: What Does It Feel Like?
The heat index (also called 'feels like' temperature) combines air temperature and relative humidity to describe how hot it actually feels to the human body. High humidity reduces the body's ability to cool itself through sweating, making the perceived temperature much higher than the actual air temperature.
Common Uses
- Understanding outdoor safety during hot weather
- Planning outdoor events, sports, and activities
- Assessing heat stress risk for workers
- Weather reporting and meteorology
Frequently Asked Questions
What are heat index danger levels?
Caution: 80–90°F (fatigue possible). Extreme Caution: 90–103°F (heat cramps/exhaustion possible). Danger: 103–124°F (heat cramps/exhaustion likely). Extreme Danger: 125°F+ (heatstroke highly likely). Stay hydrated and limit outdoor activity when the heat index is high.
How is the heat index calculated?
The NWS uses a multi-variable regression equation developed by Steadman (1979) with temperature and relative humidity as inputs. The formula includes 9 terms and is most accurate for temperatures above 80°F and relative humidity above 40%.
Is this calculator free to use?
Yes. All calculators on zenicalculator.com are completely free with no registration required.
Google Ad (Bottom)