Discomfort Index Calculator

Calculate how hot it feels when accounting for relative humidity. The Discomfort Index estimates the apparent temperature based on heat and humidity.

Input Parameters

Calculation Results

Calculation Formula

DI = -42.379 + 2.04901523 × T + 10.14333127 × R - 0.22476926 × T × R - 0.00683783 × T² - 0.05481717 × R² + 0.00122874 × T² × R + 0.0007165 × T × R² - 0.00000345372 × T² × R²

Where:
DI = Discomfort Index
T = Temperature (°F)
R = Relative Humidity (%)

Result

Discomfort Index: --
Apparent Temperature: --

Comfort Level

--

Discomfort Index Calculator Usage Guide

Learn how to use the Discomfort Index Calculator and understand how temperature and humidity affect perceived temperature.

What is the Discomfort Index?

The Discomfort Index, also known as the Heat Index, estimates how hot it feels when accounting for both temperature and relative humidity. High humidity makes hot temperatures feel much hotter because sweat cannot evaporate efficiently from the skin, which is our body's natural cooling mechanism.

How to Use This Calculator

  1. Enter the current temperature. You can choose between Celsius (°C) or Fahrenheit (°F).
  2. Enter the current relative humidity percentage.
  3. Click the "Calculate" button to see the estimated Discomfort Index and apparent temperature.
  4. The calculator will also indicate the comfort level based on the calculated value.

Understanding the Results

  • Discomfort Index (DI): This value represents how hot it feels, combining the effects of temperature and humidity.
  • Apparent Temperature: This is essentially the same as the Discomfort Index in this calculator.
  • Comfort Level: Provides a qualitative assessment of how uncomfortable the conditions are:
    • Green (Comfortable): DI < 65°F
    • Yellow (Moderately Uncomfortable): 65°F ≤ DI < 75°F
    • Orange (Uncomfortable): 75°F ≤ DI < 85°F
    • Red (Very Uncomfortable/Dangerous): DI ≥ 85°F

Principle and Formula

This calculator uses the Steadman formula, which is widely accepted for calculating the Heat Index. The formula considers both temperature and humidity to provide a more accurate representation of perceived temperature than either factor alone.

Safety Tips

When the Discomfort Index is high (especially above 75°F), it's important to take precautions:

  • Stay hydrated by drinking plenty of water
  • Limit outdoor activities during the hottest part of the day
  • Wear lightweight, loose-fitting clothing
  • Take frequent breaks in cooler areas
  • Check on vulnerable individuals (elderly, children, those with medical conditions)