# Heat Index

> Calculate the 'feels like' temperature by combining air temperature and relative humidity.

Page: https://askcalculators.com/calculator/heat-index-calculator/
Definition: https://askcalculators.com/calculator/heat-index-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/heat-index-calculator/schema.json
Version: 7.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/heat-index-calculator/?temp=90&humidity=60

## Inputs
- temp: Temperature (°F); type=number; optional; default=90
- humidity: Relative Humidity (%); type=number; optional; default=60

## Outputs
- result: Result; format=text; primary

## Formula
Heat index uses the NOAA Rothfusz regression with temperature and relative humidity.

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.