# Heat Index - HI — Feeling hot or cold

> Calculates apparent temperature using air temperature and humidity with the Rothfusz equation. (iPhone/iPad app by LionsApp di Nallbati Elton.)

- Source: https://appshunter.io/ios/app/heat-index-hi/id1480149233 (this page in markdown: same URL + `.md`)
- Developer: [LionsApp di Nallbati Elton](https://appshunter.io/developer/432915499)
- Category: Weather, Health & Fitness
- Price: $2.99
- Rating: 3.90/5 from 9 App Store ratings · 3 written reviews indexed
- Age rating: 4+
- Requires: iOS 11.0 · 6 MB
- Languages: American English, Danish, Dutch, Finnish, French (France), German (Germany), Italian, Japanese, Norwegian Bokmål, European Portuguese and 4 more
- Released: 2020-06-21
- Data updated: 2026-09-07
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/heat-index-hi/id1480149233/reviews.md

## What is Heat Index?

The first "Heat Index" tool that uses the Lans P. Rothfusz equation.

[Description]
The heat index (HI) is an index that combines air temperature and relative humidity, in shaded areas, that is the feeling of "hot" or "cold" that is felt; it is due not only to the air temperature, but also to other environmental conditions, such as humidity and wind.

The heat index was developed in 1979 by Robert G. Steadman.
The computation of the heat index is a refinement of a result obtained by multiple regression analysis carried out by Lans P. Rothfusz and described in a 1990 National Weather Service (NWS) Technical Attachment (SR 90-23).

The heat index is also known as the "felt air temperature", "apparent temperature", "real feel" or "feels like".
The humidity in the air can increase the sensation of heat, while the wind can increase the sensation of cold.
For example, when the temperature is 32°C (90°F) with 70% relative humidity, the heat index is 41°C (106°F).

[How does it work]
Wherever you are, you will have the Heat Index, temperature, humidity and weather conditions.
Search for new locations and they will automatically be added to your favorites.
Make sure you have activated the location services on your device, at this point the App will detect your geographical position.

[Features]
- Heat Index calculated with the Rothfusz equation
- Temperature
- Humidity
- Effects of the Heat Index
- Choice of 3 units of measurement: celsius, fahrenheit and kelvin
- Map current location
- Search City (without limits)
- Save favorite places (without limits)
- Intuitive graphics
- Ease of use

[Supported languages]
English, Italian, Spanish, French, German, Portuguese, Dutch, Russian, Chinese, Japanese, Danish, Finnish, Norwegian, Swedish.

[Support]
If you need help please do not hesitate to contact us at info@lionsapp.com, or visit www.lionsapp.com
If you like the App, don't forget to leave us a comment on the App Store.

## Key features

- Heat Index calculation (Rothfusz equation)
- Current temperature and humidity
- Choice of Celsius, Fahrenheit, and Kelvin
- Map current location
- Search and save unlimited favorite cities
- Intuitive graphics and ease of use

## Recent user reviews (3 of 3)

All indexed reviews: https://appshunter.io/ios/app/heat-index-hi/id1480149233/reviews.md

### 1/5 — Great But

*2024-07-10*

Love the way it works but doesn’t work or can be added to the Apple Watch. Also doesn’t have a widget. Overall it does the job but can be better. Update, doesn’t work.

### 2/5 — Funktioniert nur unter 30 grad

*2022-06-27*

Hallo

Der Hitzeindex funktioniert ja nur bis Temperaturen unter 30° c .  Danach kommt immer Gleichung kann nicht angewendet werden. Was soll das bitte schön?  
Eigentlich ist diese App damit Schrott. 
Man sollte mal eine Überarbeitung in Angriff nehmen. 
Optisch gut aufbereitet. Deshalb noch 2 Sterne.

**Developer response:** Hallo, könnten Sie uns unter info@lionsapp.com kontaktieren, damit wir Ihnen helfen können. Vielen Dank !

### 5/5 — Unique design Heat Index app

*2021-03-31*

Thanks to the Developer for putting out a very unique outstanding design 5 star app! This app not only gives you and myself the Heat Index information for our area you and myself are in. But I find not only is the information for my area as they say correct but the Developer shows it in a beautiful unique way that is of 5 star quality! I hope you will download this app today now! I don’t think you will be disappointed or sorry! (Really) once again I thank the Developer it really really is a nice app! Thanks

**Developer response:** Hello and thank you very much for your appreciation !

## Frequently asked questions about Heat Index

### What is the Heat Index app?

The Heat Index app calculates the "felt air temperature" by combining air temperature and relative humidity using the Rothfusz equation. It provides users with a more accurate understanding of how hot or cold it truly feels.

### What units of measurement does the Heat Index app support?

The Heat Index app supports three units of measurement: Celsius, Fahrenheit, and Kelvin. This allows users to view the heat index in their preferred scale.

### Can I use the Heat Index app without activating location services?

While the app can detect your geographical position with location services activated, you can also search for new locations and add them to your favorites. This allows you to check the heat index for cities worldwide.

### How accurate is the Heat Index calculation?

The app uses the Lans P. Rothfusz equation, which is a refinement of a result obtained by multiple regression analysis by Lans P. Rothfusz and described in a 1990 National Weather Service (NWS) Technical Attachment. This provides a scientifically based calculation of the heat index.

### Does the Heat Index app have ads?

No, the Heat Index app does not contain advertisements. It is a paid application designed to provide a focused weather experience without interruptions.

### What is the price of the Heat Index app?

The Heat Index app is available for a one-time purchase of $3.99. This grants you full access to all its features without any recurring fees or in-app purchases.

### How often is the Heat Index app updated?

The latest version of the Heat Index app is 1.2, which was last updated on August 4, 2020. While updates may not be frequent, the core functionality remains stable and reliable.

### What devices is the Heat Index app compatible with?

The Heat Index app is compatible with iPhones, iPads, and iPods. It is designed for iOS devices and requires iOS 4+.

## Version history (last 3 releases)

### 1.2 — 2020-08-04

+ Fixed a problem on iPad 10.2", the preferred location would not be loaded once selected

### 1.1 — 2020-07-29

+ Fixed an issue with the name of the current location

### 1.0 — 2020-06-21

No release notes.

## Apps similar to Heat Index

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [WeatherCyclopedia™ Premium](https://appshunter.io/ios/app/weathercyclopedia-premium/id305728705) | 3.7 (3) | $13.99 | Weather |
| [Heat Index & Category Computer](https://appshunter.io/ios/app/heat-index-and-category-computer/id370913314) | 5.0 (1) | Free | Weather |
| [Weather & Forecast: Breeze](https://appshunter.io/ios/app/weather-and-forecast-breeze/id6764819398) | — | Free | Weather |
| [WBGT Estimator](https://appshunter.io/ios/app/wbgt-estimator/id6739461541) | 4.0 (1) | $0.99 | Weather |
| [Wind & Wave NW](https://appshunter.io/ios/app/wind-and-wave-nw/id6749160700) | 5.0 (2) | $0.99 | Weather |
| [Radar Storm Weather Forecast](https://appshunter.io/ios/app/radar-storm-weather-forecast/id6760627910) | — | $2.99 | Weather |

## More apps by LionsApp di Nallbati Elton

- [Search IP](https://appshunter.io/ios/app/search-ip/id433032502)
- [Fahrenheit Celsius](https://appshunter.io/ios/app/fahrenheit-celsius/id433493463)
- [Wash - Laundry symbols](https://appshunter.io/ios/app/wash-laundry-symbols/id434699707)
- [Contact Lenses Pro](https://appshunter.io/ios/app/contact-lenses-pro/id439360542)
- [Mile Km](https://appshunter.io/ios/app/mile-km/id444093610)
- [Contact Lenses](https://appshunter.io/ios/app/contact-lenses/id446322112)

All apps by LionsApp di Nallbati Elton: https://appshunter.io/developer/432915499

---

*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-07.*