Wind Chill / Heat Index Calculator
Find the approximate feels-like temperature for cold windy conditions or hot humid weather.
Educational estimate. Calculator results are for planning and information only, not financial, tax, medical, legal, or engineering advice. Verify important decisions with official sources or a qualified professional.
Wind Chill / Heat Index Calculator
Feels Like Temperature
📐 Formula & Method
Wind Chill
T is air temperature in deg F and V is wind speed in mph. Use only at T <= 50 deg F and V >= 3 mph.
Heat Index
Use only at T >= 80 deg F and relative humidity >= 40%. Values are shade-based apparent temperature estimates.
📋 How to Use
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1
Enter the required values.
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2
Check the units and selected option.
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3
Click Calculate to see the result and useful breakdown.
🧮 Worked Examples
Validation case
Wind chill with 35 deg F and 15 mph wind.
Wind Chill / Heat Index Calculator Guide
This calculator is designed for fast everyday estimates while keeping the formula visible and easy to verify.
Results are calculated in your browser and are intended for planning, learning, and comparison. For regulated financial, tax, medical, legal, or construction decisions, confirm details with a qualified professional.
🔬 Methodology & Accuracy
Formula: Selects either the NWS wind chill equation or Rothfusz heat-index regression and validates that inputs are inside the accepted range before calculating.
Data sources: National Weather Service wind chill equation and Rothfusz heat-index regression.
Last reviewed: June 2026 · General formula used: Wind Chill · Accuracy: Results are precise to two decimal places using IEEE-754 double-precision arithmetic. Intended for educational and planning use only.
For informational purposes only. Results are estimates based on the inputs and formulas provided. For financial, tax, medical, or legal decisions, consult a qualified professional. Rates and regulations change — always verify current figures with official sources.