What Does 'Feels Like' Temperature Mean? Wind Chill vs Feels Like Explained

Quick Answer: What "Feels Like" Means

Feels-like temperature, also called apparent temperature, is an estimate of how the air feels on your body once wind, humidity, or both are taken into account. It is an umbrella term. Wind chill and heat index are the two best-known formulas underneath it.

Term	What it adds to air temperature	When it applies
Wind chill	Wind, which strips heat from exposed skin	NWS formula: 50°F or colder, wind above 3 mph
Heat index	Humidity, which slows the evaporation of sweat	Warm and humid conditions
Feels like	Whichever of the two fits the conditions, or a broader model that blends wind, humidity, and sometimes sunshine	Any time of year

So wind chill vs feels like is not really a contest. On a cold, windy day the feels-like number in a weather app usually is the wind chill. On a hot, humid day it usually is the heat index. In between, some providers show the plain air temperature and others run a broader apparent-temperature model.

Every one of these numbers is an estimate under a model's assumptions. Your clothing, activity, health, and exposure also matter, and a feels-like reading cannot certify that an outdoor activity is safe.

Wind Chill: Heat Loss in Cold Wind

Your body is always losing heat to colder air. In calm conditions a thin layer of air warmed by your skin slows that loss. Wind sweeps the layer away, so you lose heat faster. The NWS wind chill index expresses that faster heat loss as a temperature.

The current index took effect on 1 November 2001. It replaced a formula based on 1945 Antarctic research, and it was tested on volunteers in a chilled wind tunnel. The formula is:

Wind chill (°F) = 35.74 + 0.6215T - 35.75(V^0.16) + 0.4275T(V^0.16)

T is the air temperature in °F and V is the wind speed in mph. The index is defined only for air temperatures of 50°F or below and wind speeds above 3 mph.

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Two things stand out on the chart.

Wind matters more as it gets colder. A 20 mph wind takes 30°F down to a wind chill of 17°F, a 13-degree drop. The same wind takes 0°F down to -22°F, a 22-degree drop.

The first few miles per hour do the most. At 0°F, going from calm to 10 mph costs 16 degrees. Going from 30 mph to 40 mph costs 3 more.

The index also carries assumptions worth knowing. It models an adult face about 5 feet above the ground, and it assumes a clear night sky. Bright sunshine can make it feel 10 to 18°F warmer than the wind chill value. Wet clothing works in the other direction, and prolonged exposure can cause cold stress at wind chills well above the frostbite zones.

Try your own numbers in the wind chill calculator, or see the short definition in our glossary.

Frostbite Times on the NWS Chart

The National Weather Service chart shades three zones that show how long exposed skin can last before frostbite develops: 30 minutes, 10 minutes, and 5 minutes. The zones depend on air temperature and wind speed together. A single wind chill cutoff does not capture them, because the same wind chill can sit in different zones at different wind speeds.

A few points read off the chart:

Conditions	Wind chill	Frostbite on exposed skin
0°F with a 15 mph wind	-19°F	About 30 minutes
-15°F with a 20 mph wind	-42°F	About 10 minutes
-25°F with a 30 mph wind	-60°F	About 5 minutes

Two limits apply to every row. Frostbite requires an air temperature below freezing: a wind chill of 25°F on a 35°F day will not freeze skin, although hypothermia is still possible. And the chart describes bare skin, so covering your face, ears, and hands changes the picture more than anything else you can do.

Read your own combination from the NWS chart instead of working from a wind chill value alone.

What Happened to the Wind Chill Warning?

If you went looking for a Wind Chill Warning last winter and found none, nothing is broken. The National Weather Service retired all three wind chill alert products on 1 October 2024 and replaced them with a new set of cold alerts.

Retired on 1 October 2024	Replaced by
Wind Chill Watch	Extreme Cold Watch
Wind Chill Warning	Extreme Cold Warning
Wind Chill Advisory	Cold Weather Advisory
Hard Freeze Watch	Freeze Watch
Hard Freeze Warning	Freeze Warning

The reason is in the names. The old products were tied to wind chill, and a wind chill headline needed a minimum wind speed, so dangerous cold on a calm night did not fit. The new products are issued on the air temperature or the wind chill, whichever applies, with no minimum wind speed. Cold is dangerous with or without wind, and the alerts now say so.

Extreme Cold Warning vs Cold Weather Advisory

The three new products follow the usual watch, warning, and advisory pattern:

• Extreme Cold Watch: extremely dangerous cold or wind chill values are possible, but the timing or location is still uncertain. Get ready.
• Extreme Cold Warning: extremely dangerous cold or wind chill values are expected or already happening. Act now.
• Cold Weather Advisory: it will be dangerously cold, but below the warning level for your area. Take precautions.

There are no nationwide trigger values. Each forecast office sets criteria from its local climate, so the same alert means very different numbers in different places. The Twin Cities office issues an Extreme Cold Warning when air temperatures or wind chills are expected to fall below -35°F in the metro area and to its south and east, and below -40°F to the north and west. The New Orleans office issues one when they are expected to fall below 15°F along and south of Interstate 10, and its Cold Weather Advisory starts below 25°F there. Your local NWS office publishes the criteria for where you live.

Wind chill itself has not gone anywhere. Forecasters still calculate it, and it is one of the two measures that can trigger the new alerts. Only the product names changed. For a related name change at the mild end of the cold season, see our guide to frost advisories and freeze warnings.

Heat Index: Temperature and Humidity Together

The heat index combines air temperature and relative humidity to estimate apparent warmth. Your body cools itself by evaporating sweat, and humid air slows that evaporation.

The NWS calculation does not simply switch on when the air temperature reaches 80°F. It first calculates a simpler estimate and averages that with air temperature. If that result reaches 80°F, it uses the full regression and applicable adjustments. For example, 79°F at 95% relative humidity produces a heat index of about 83°F. See the WPC calculation method.

The standard heat index assumes shade and light wind. The NWS says full sunshine can increase its effect by up to 15°F. That is a variable effect, not an instruction to add a fixed amount to every reading. At 90°F and 70% humidity, the heat index is about 106°F; a hypothetical 15-degree increase would be 121°F. Both are within the NWS chart's Danger range. See the NWS heat index explanation.

A lower index does not guarantee safety during strenuous activity or prolonged exposure. Our heat safety guide has the full chart and explains the categories and their limits. The heat index calculator lets you explore different temperature and humidity combinations.

Mild Weather Still Has Wind and Humidity Effects

Between the usual cold-weather and hot-weather index ranges, wind, moisture, and sunlight continue to affect comfort. There is no physical zone where those effects switch off.

Some providers return air temperature in mild conditions; others use a broader apparent-temperature model. The Bureau of Meteorology's thermal comfort documentation illustrates why the variables and assumptions of a particular method matter. This is also why two apps can show different feels-like numbers for the same place at the same moment: they may be using different formulas, different forecast inputs, or both.

Dew point is another useful description of moisture in the air, but it is not a complete comfort or safety measure. Compare it with temperature, wind, and your planned activity. Our dew point guide explains the difference between dew point and relative humidity.

Wet-Bulb Temperature Is a Different Measurement

A ventilated thermometer with a wet covering cools through evaporation. Its wet-bulb reading reflects temperature and humidity together. It is distinct from wet-bulb globe temperature (WBGT), which also accounts for radiant heat and is used in occupational and sports heat assessments. The Bureau of Meteorology describes these measurements and their limitations.

The often-quoted 35°C (95°F) wet-bulb limit is not a safe-exposure threshold. In laboratory tests, young, healthy adults reached uncompensable heat stress below that value. The threshold varied with the environmental conditions, so the study does not establish one universal boundary for safe outdoor activity. See the PSU HEAT Project study.

Age, health, activity, clothing, wind, and sunlight also influence risk. A simple wet-bulb calculator cannot incorporate all of them, and a reading below a published research threshold does not establish that someone is safe.

Use our wet-bulb calculator for an estimate from temperature and humidity, alongside the limitations shown with its result.

Wind Chill Myths: Pipes, Car Batteries, and the Old Formula

"Wind chill will freeze my pipes"

Wind chill describes heat loss from skin. It is not a temperature that objects reach. Wind does make an exposed pipe lose heat faster, so in below-freezing air the pipe gets to freezing sooner. It never gets colder than the air around it. If the air is 35°F and the wind chill is 25°F, the pipe stops cooling at 35°F and does not freeze. Insulation, water flow, exposure, and how long the cold lasts matter more than the wind chill number.

"My car won't start because of the wind chill"

A battery, an engine block, and a radiator all follow the same rule as the pipe. Wind helps a parked car shed its leftover engine heat faster, but nothing under the hood drops below the air temperature. The NWS gives an example: with the air at -5°F and a wind chill of -31°F, a car radiator will not fall below -5°F. Plan for the forecast low, not the wind chill.

"The old wind chill numbers were more accurate"

They were colder, not better. The pre-2001 index came from 1945 measurements of how fast a container of water cooled on a pole in Antarctica. Water in a container freezes faster than skin does, so the old index overstated the chilling effect of wind. The current index is built on heat loss from a human face and was checked against people walking on a treadmill in a wind tunnel. An old wind chill value cannot be converted to a new one by itself: you need the original air temperature and wind speed.

Using the Numbers for Outdoor Plans

Look at the expected conditions throughout the activity, including the hottest or coldest part of the day. Consider exposure to sun, wind, and rain as well as whether shade, shelter, water, and a way to stop are available. Follow local weather alerts and the guidance appropriate to your activity.

When you pack for a trip, check the feels-like forecast along with the highs and lows. A destination at 35°F with a 20 mph wind has a wind chill of about 24°F, and that is the number to dress for. Your car and your luggage only care about the 35.

For outdoor work, heat index alone cannot set a universal work-and-rest schedule. NIOSH recommends reducing heat exposure, providing cool recovery areas and drinking water, adjusting workload, training workers, and allowing gradual acclimatization. Its workplace recommendations explain why the job and worksite need their own assessment.

Human weather indices also do not establish safe pavement temperatures or universal exposure limits for pets. Their needs vary with species, breed, health, and conditions; use veterinary guidance when planning their care.

Frequently Asked Questions

What does feels-like temperature mean?

Feels-like temperature is an estimate of how the air feels on your body after accounting for more than the thermometer reading. In cold, windy weather it reflects wind chill, the extra heat your skin loses to moving air. In hot, humid weather it reflects the heat index, which accounts for sweat evaporating more slowly. It is a model of the average person, so your clothing, activity, and health change how it applies to you.

Is wind chill the same as feels like?

Wind chill is one kind of feels-like temperature. Feels like is the general term, and wind chill is the specific NWS formula for cold air (50°F or below) with wind above 3 mph. When conditions are cold and windy, the feels-like value in most weather apps is the wind chill or something close to it. In warm weather the same label usually shows the heat index instead.

What happened to the Wind Chill Warning?

The National Weather Service retired the Wind Chill Watch, Wind Chill Warning, and Wind Chill Advisory on 1 October 2024. They were replaced by the Extreme Cold Watch, Extreme Cold Warning, and Cold Weather Advisory. The new alerts can be issued for dangerous cold with or without wind, based on either the air temperature or the wind chill. Wind chill is still calculated, and it can still trigger an alert.

What is the difference between an Extreme Cold Warning and a Cold Weather Advisory?

An Extreme Cold Warning is the more serious of the two. It means extremely dangerous cold or wind chill values are expected or already occurring. A Cold Weather Advisory means it will be dangerously cold but below the warning level for that area. The numbers behind each one are set by the local NWS forecast office from the local climate, so they differ widely between, say, Minnesota and Louisiana.

At what wind chill does frostbite happen?

On the NWS wind chill chart, the 30-minute frostbite zone begins at wind chills near -20°F, with the exact point depending on the wind speed. The standard example is 0°F with a 15 mph wind, a wind chill of -19°F, where exposed skin can freeze in about 30 minutes. At -15°F with a 20 mph wind the time drops to about 10 minutes. Frostbite also requires the air temperature itself to be below freezing.

Can wind chill freeze pipes or make a car colder than the air?

No. Wind chill applies to people and animals. Wind makes an object cool down faster, but the object cannot drop below the actual air temperature. A pipe in 35°F air will not freeze no matter how strong the wind is, and a car radiator in -5°F air stops cooling at -5°F even when the wind chill is -31°F.

Why do two weather apps show different feels-like temperatures?

Feels like is not one standard formula. Some sources report the NWS wind chill or heat index, and others use a broader apparent-temperature model that can include humidity in cold weather or sunshine in any weather. The forecasts feeding the formula can differ as well. A gap of a few degrees between two sources is normal.

What WeatherAI Displays

WeatherAI displays a feels-like temperature from the forecast provider you select. The provider's method and forecast inputs can differ from those used in an NWS product, so there is no guaranteed match between them.

Official National Weather Service alerts are free in the app, with push notifications for your current location and up to 10 saved locations. Cold alerts appear under the names the NWS uses now.

You can also build custom feels-like rules on the Standard and Pro plans. A rule checks one threshold at a time of day you choose. It is supplemental information, and does not guarantee advance notice of every dangerous condition.

The calculators linked in this article are tools on the WeatherAI website. Use them to understand the indices, and use official local guidance for weather-related safety decisions.

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Sources

• National Weather Service: Understanding Wind Chill, the Wind Chill Temperature Index brochure, and wind chill questions
• National Weather Service: revised watch, warning, and advisory products for cold and Understanding Cold Weather Alerts
• Local criteria examples: NWS Twin Cities and NWS New Orleans/Baton Rouge
• Weather Prediction Center: the heat index equation

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Getting ready for winter? Read why snow total forecasts vary, what the polar vortex is, and our winter weather guide.