Where can I find historical heat index and wind chill data?

Historical heat index and wind chill information is available in Visual Crossing Weather through the feelslike weather element. This field represents apparent temperature: in hot and humid conditions it reflects heat-index effects, while in cold and windy conditions it reflects wind-chill effects. Historical, current, and forecast feels-like temperature can be retrieved using the Visual Crossing Weather Data tools or the Timeline Weather API.

How are heat index and wind chill data used?

Heat index and wind chill are two ways of describing how weather conditions can make the air feel different from the measured temperature. Heat index combines temperature and humidity to represent apparent temperature during hot, humid conditions. Wind chill combines temperature and wind speed to represent apparent temperature during cold, windy conditions.

Visual Crossing combines these apparent-temperature calculations into the feelslike field. Applications therefore do not need to switch between separate heat-index and wind-chill fields. When neither adjustment is applicable, feelslike generally remains close to the actual air temperature.

How is feels-like temperature reported?

feelslike is returned as a temperature using the units selected by the request. For example, unitGroup=us returns temperature values in degrees Fahrenheit, while unitGroup=metric returns degrees Celsius.

Visual Crossing currently applies heat-index logic under sufficiently hot and humid conditions and wind-chill logic under sufficiently cold and windy conditions. In other conditions, feelslike generally remains close to the measured air temperature.

Wind-chill calculations apply during sufficiently cold and windy conditions. Visual Crossing currently applies wind-chill logic when the air temperature is below approximately 50°F (10°C) and wind speed exceeds approximately 3 mph (5 km/h). Under these conditions, feelslike may be lower than the measured air temperature.

How can I find historical feels-like temperature for a location and date?

The easiest no-code option is the Visual Crossing Weather Query Builder. Enter the location, choose the historical date or date range, and select the weather elements you need. You can preview the results in your browser and download the resulting weather dataset for analysis in Excel or other tools.

If you do not already have an account, you can sign up for Visual Crossing Weather.

For automated applications, use the Timeline Weather API. The API can return historical, current, and forecast feels-like temperature in JSON, CSV, and other supported formats.

For example, this request retrieves daily temperature and apparent-temperature values:

https://weather.visualcrossing.com/VisualCrossingWebServices/rest/services/timeline/Chicago,IL/2026-01-01/2026-01-07?unitGroup=us&include=days&elements=datetime,temp,tempmax,tempmin,feelslike,feelslikemax,feelslikemin&key=YOUR_API_KEY

What is the difference between temp and feelslike?

temp is the measured or modeled air temperature.

feelslike is the apparent temperature after applying the appropriate heat-index or wind-chill calculation when conditions warrant it.

For example:

temp = 94°Ffeelslike = 105°F

indicates hot and humid conditions where the apparent temperature is higher than the measured air temperature.

Similarly:

temp = 25°Ffeelslike = 14°F

indicates cold, windy conditions where wind chill lowers the apparent temperature.

Summary

Historical heat index and wind chill information is available in Visual Crossing Weather through the unified feelslike field.

Use feelslike for hourly and other individual records, and feelslikemax, feelslikemin, and feelslike for daily apparent-temperature summaries.

In hot and humid conditions, feelslike reflects heat-index effects. In cold and windy conditions, it reflects wind-chill effects.

You can retrieve these values using Visual Crossing Weather Data or the Timeline Weather API.