Reproduce the NWS Wind Chill Temperature Index from documented temperature and wind speed with exact units, source context, and no safety prediction.
Specialist tool for Climbing1 documented formula8 real workflowsPrivate in your browser
Use this result well
A quick decision brief for this specific tool
Inputs that matter
One record name/revision, exact condition context, accountable weather-input source, condition date and location; air temperature in °F or °C; wind speed in mph, km/h, m/s or international knots; one display-rounding rule; optional reported index plus its source label; and four explicit formula/input/interpretation/decision boundaries
Output to expect
Exact normalized °F/°C and mph/km/h inputs, V^0.16, unrounded and rounded NWS Wind Chill Temperature Index, signed index-minus-air-temperature delta, optional calculated-minus-reported difference and a Project v1 arithmetic record
How it works
Normalize the documented inputs to °F and mph, enforce the NWS-defined domain of air temperature at or below 50°F and wind speed above 3 mph, then reproduce `35.74 + 0.6215T − 35.75V^0.16 + 0.4275TV^0.16` and apply only the selected display rounding
Use one accountable source, date, location and exact condition pair. Do not invent, combine or guess a headwind, gust, travel speed or exposure input; keep any optional reported index together with its source label.
The result is not a forecast, official warning, frostbite timer, personal cold-risk class, clothing/activity/exposure prescription, medical or treatment instruction, emergency response or go/no-go safety decision. Retain it with current official weather information and accountable review.
Choose your path
Built around the job you need to finish
Reproduce the published NWS Wind Chill Temperature Index from one documented air temperature and wind speed, with explicit unit normalization, rounding and optional sourced comparison while refusing every frostbite timer, personal-risk score, forecast, warning, treatment and go/no-go decision.
Weather communicator reproducing a forecast value
Show the exact published equation and unit normalization behind one retained wind-chill index without creating a new forecast.
Record the forecast owner, date, point and context, enter temperature and wind in their documented units, select rounding, inspect every formula term and export the arithmetic record.
Can explain the calculation and source context while forecast issuance, warning criteria and public guidance remain with the weather authority.
Keep one source-owned weather input pair and its index traceable without allowing the Tool to decide whether an activity proceeds.
Enter the accountable source and location, confirm the NWS domain and four decision boundaries, retain the result with the official forecast and hand the record to a Project.
Gets a reviewable arithmetic record with no frostbite timer, clothing prescription, exposure limit, treatment instruction or go/no-go conclusion.
Educator or auditor comparing a reported index
Check whether one displayed index matches the current published formula after exact unit conversion and declared rounding.
Load the de-identified example, exercise °F/°C and mph/km/h/m/s/knot inputs, add a reported value with its source label, trigger domain/tuple/date/boundary errors and inspect nondecisions.
Can separate arithmetic or rounding differences from weather, health and safety interpretation without presenting simulated paths as real-user research.
Authoritative checks for this tool
Outputs and checklists are planning aids. Review the linked current authorities and the records, terms, instructions, and requirements that apply to your exact situation before a consequential decision.
The current NWS national page defines Wind Chill Temperature only when air temperature is at or below 50°F and wind speed is above 3 mph. Inputs outside that domain are refused rather than echoed or extrapolated.
Temperature is normalized from °C or °F to °F. Wind speed is normalized from mph, km/h, m/s or international knots to mph. Both normalized values remain visible beside the result.
°F = °C × 9/5 + 32; mph = entered speed × disclosed unit factor
Keep arithmetic separate from action
The Tool shows the unrounded index, selected display rounding, signed difference from air temperature and an optional sourced reported-index difference. Forecasts, warnings, exposure time, symptoms and decisions remain external.
Arithmetic record ≠ forecast, frostbite timer, personal-risk score or go/no-go decision
Updated: September 2026
Example Scenarios
Retain the forecast owner, date, point, temperature and wind speed; reproduce the equation and declared rounding without issuing a new forecast or warning.
Attach the arithmetic record to current official weather information and accountable review. The Tool does not approve, cancel or alter an activity.
Enter one reported index with its source label and inspect the signed formula difference after exact unit normalization; do not treat a mismatch as a safety conclusion.
Common Mistakes to Avoid
✕
Entering a guessed or combined wind speed
✓
Retain one accountable source, date, location and exact condition pair. Do not silently add travel speed, gusts or values from another forecast point.
✕
Turning the index into a personal safety timer
✓
Keep the output as formula arithmetic. Forecasts, warnings, health risk, exposure limits, clothing, treatment and go/no-go decisions belong to current official guidance and accountable reviewers.
FAQ
It reproduces the current NWS Fahrenheit/mph equation shown in the method card. It does not blend that equation with a separate publisher's risk bands or warning criteria.
The NWS national page defines Wind Chill Temperature only at air temperatures at or below 50°F and wind speeds above 3 mph. The Tool enforces that published domain.
Not here. Use one documented air-temperature and wind-speed pair owned by an accountable source. Invented or silently combined inputs are refused by the record boundary.
No. It only subtracts one fully sourced reported index from the calculated value. Source timing, rounding, input selection and forecast validity require separate review.
No. The Tool does not estimate exposure time or personal risk and does not prescribe clothing, activity, treatment or emergency action. Use current official weather and accountable safety guidance.
About NWS Wind Chill Index Record
Reproduce the published National Weather Service Wind Chill Temperature equation for one documented air-temperature and wind-speed pair. The record retains source, date, location, units, rounding and an optional reported-index comparison. It does not create a forecast, frostbite timer, personal-risk score or activity decision.
