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Heat Index Calculator

Science & Engineering

NOAA feels-like temp, risk levels

Quick Answer

Heat Index Calculator: NOAA feels-like temp, risk levels. Heat Index Calculator uses standard science & engineering formulas to compute accurate results instantly.

℃
%
Feels-like (heat index)
43.5 ℃
Danger · 10.5 ℃ hotter than actual

Calculation steps

  1. 1Convert: 33 ℃ = 91.4 ℉, RH = 70%
  2. 2Heat index = 43.5 ℃ (110.2 ℉)
  3. 3Risk level: Danger

Heat index matrix (℃)

Temp \ RH40%50%60%70%80%90%
30℃303133353841
33℃343640434854
35℃374145505764
38℃434955637181
40℃485563728395
Humidity blocks sweat evaporation — at 33 ℃/70% RH it feels like 41 ℃. The heat index assumes shade and light wind; direct sun can add up to 8 ℃. Winter counterpart: wind chill. Drink water before you feel thirsty; above 41 ℃ apparent temperature, move all outdoor work to morning/evening.

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How to Use

  1. Enter known quantities: fill values and confirm units in the Heat Index Calculator.
  2. Instant solution: unknowns solve live with the formula shown transparently.
  3. Use constant/material tables: standard physical constants and material data are listed on this page.
  4. Compare conditions: change inputs to compare scenarios.

Key Points

  • Heat Index Calculator is a free online science & engineering tool — open and use, no sign-up.
  • All calculations run locally in your browser; your data never leaves the device.
  • Key capability: NOAA feels-like temp, risk levels.
  • Results come with formulas and reference tables so you can verify every number.

Formula & How It Works

Heat Index Calculator formula

Heat Index Calculator uses standard science & engineering formulas to compute accurate results instantly.

FAQ

How do I use the Heat Index Calculator?
Open the page and fill in the input fields — results update automatically. NOAA feels-like temp, risk levels.
Are the results accurate?
Yes. Standard formulas and conversion factors are used and verified.
Is it free? Do I need to sign up?
Completely free. No registration, login or download required.
Does it work on mobile?
Yes. The responsive design works on phones, tablets and desktops.
Is my data saved?
No. Everything runs locally in your browser.

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Source & Updates

Based on CODATA recommended constants and standard physics formulas. Last updated: 2025-07

Last updated:

Formulas and content on this page are reviewed by the YiJianSuan team. For reference only — official sources prevail.

Maintained and periodically reviewed by the YiJianSuan editorial team — review process in ourEditorial Policy.

Cite this page: YiJianSuan. Heat Index Calculator[EB/OL]. https://www.yijiansuan.com/en/c/science/heat-index

Results provided by this tool are for reference only and do not constitute professional advice.