Feels Like Temperature Calculator
Calculate feels-like temperature using heat index or wind chill from actual temperature, humidity, and wind speed.
Covers both Fahrenheit and Celsius input.
“Feels like” temperature combines two separate formulas depending on conditions: Wind Chill for cold weather and Heat Index for hot, humid weather. Neither applies in mild conditions — only one formula is active at a time.
Wind Chill (applies when T ≤ 10°C / 50°F and wind > 4.8 km/h): WC = 13.12 + 0.6215T − 11.37V^0.16 + 0.3965T × V^0.16
Where:
- T = air temperature (°C)
- V = wind speed (km/h)
Wind chill works by accelerating heat loss from exposed skin. A 20°C temperature with 30 km/h winds feels like 12°C because moving air strips away the warm boundary layer near the skin.
Heat Index (applies when T ≥ 27°C / 80°F and RH ≥ 40%): The Rothfusz regression equation (NWS standard) uses 9 constants: HI = −42.379 + 2.049T + 10.143RH − 0.2248T×RH − 0.00684T² − 0.0548RH² + 0.00122T²×RH + 0.000854T×RH² − 0.000002T²×RH²
Where T = temperature (°F) and RH = relative humidity (%).
Heat index reflects how humidity impairs the body’s ability to sweat and cool itself. At 35°C and 80% humidity, it can feel like 50°C+ — a dangerous heat stress level.
Worked example (Wind Chill): T = −5°C, V = 40 km/h WC = 13.12 + 0.6215(−5) − 11.37(40^0.16) + 0.3965(−5)(40^0.16) ≈ 13.12 − 3.11 − 17.42 − 3.06 = −10.5°C feels like
Danger thresholds:
- Wind Chill below −28°C: frostbite possible in 30 minutes
- Heat Index above 41°C: heat stroke risk; above 54°C: extreme danger