Heat Index
The felt temperature in hot weather, accounting for humidity.
What is Heat Index? The felt temperature in hot weather, accounting for humidity.
Heat index combines air temperature and relative humidity to estimate how hot the air feels to the human body. 90°F at 40% humidity has a heat index of about 91°F. 90°F at 80% humidity has a heat index of 105°F. High humidity slows sweat evaporation — your body's primary cooling mechanism — so heat feels worse. OSHA classifies heat index over 91°F as moderate caution; over 103°F as extreme caution; over 115°F as danger; over 125°F as extreme danger.
References: Wikipedia · Wikidata
Heat Index in our guides
Heat Index appears in the following WhetherWear guides:
- Summer Heat Survival: How to Dress for 90°F Days Without Wilting
- What to Wear at 100°F: Extreme Heat Outfit and Safety Guide
- What to Wear at 85°F: Outfit Guide for Hot Summer Days
- What to Wear at 90°F: Hot Weather Outfit Guide
- What to Wear at 95°F: Outfit Guide for Extreme Heat
- What to Wear by Temperature: A Decoded Guide From 100°F Down to 0°F
- What to Wear in Austin in Fall: Month-by-Month Outfit Guide
- What to Wear in Austin in Spring: Month-by-Month Outfit Guide
- What to Wear in Austin in Summer: Month-by-Month Outfit Guide
- What to Wear in Austin in Winter: Month-by-Month Outfit Guide
- What to Wear in Houston in Summer: Month-by-Month Outfit Guide
- What to Wear in Miami in Summer: Month-by-Month Outfit Guide
- What to Wear in New York City in Summer: Month-by-Month Outfit Guide
- What to Wear in San Antonio in Fall: Month-by-Month Outfit Guide
- What to Wear in San Antonio in Spring: Month-by-Month Outfit Guide
- What to Wear in San Antonio in Summer: Month-by-Month Outfit Guide
- What to Wear in San Antonio in Winter: Month-by-Month Outfit Guide
- What to Wear Running in Hot Weather: Staying Cool on Long Miles