Heat Index Calculator: Measure Felt Air Temperature

Understanding the heat index is crucial for your safety during hot and humid weather. Our Heat Index Calculator helps you determine how hot it really feels outside by combining air temperature and relative humidity. This "felt air temperature" can be significantly higher than the actual temperature, potentially leading to heat-related illnesses if you're not careful.

Use this tool to plan outdoor activities, assess workplace safety, or simply stay informed about potential heat risks. Remember, a heat index of 90°F or higher requires caution, while values above 105°F can be dangerous or even life-threatening.

Enter a value between 80°F and 120°F for accurate results.
Enter a value between 0% and 100%.

Heat Index: - °F

Understanding the Heat Index

The heat index, also known as the "feels like" temperature, takes into account both air temperature and relative humidity. It provides a more accurate representation of how the weather affects the human body. High humidity can make it harder for sweat to evaporate, reducing the body's natural cooling mechanism and making it feel hotter than the actual air temperature.

Heat Index Ranges and Precautions

Always stay hydrated, seek shade, and limit outdoor activities during extreme heat conditions. Use our Heat Index Calculator regularly to stay informed and safe during hot weather.