Is it too cold for kids to play outside?

Free Wind Chill Calculator & Frostbite Chart

Wind chill is how cold it feels on exposed skin from the combined effect of air temperature and wind, calculated with the National Weather Service formula. Enter the temperature and wind speed, or use current conditions, to see the wind chill, how fast frostbite can happen, and whether kids should go outside, limit their time, or stay inside today.

NWS wind chill formulaFrostbite risk and time to freezeGo, limit, or stay-inside call for kids

Calculate the wind chill

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Use a minus sign for below zero, for example -5.

Sustained wind, not gusts, as in a forecast (measured at 33 ft).

Try an example

Use current conditions

Your location is used only to fetch the weather from Open-Meteo and NWS alerts from weather.gov. It is not stored or sent anywhere else.

Wind chill and play verdict

Wind chill (NWS formula)

-7°F-21°C

Air 10°F with 15 mph wind (24.1 km/h)

Frostbite risk: Moderate risk

Physical discomfort. Risk of hypothermia and frostbite if outdoors for long periods of time without adequate protection. (Environment and Climate Change Canada)

Kids' outdoor play

Limit time outside

The wind chill is -7°F (-21°C), which is moderate risk on Environment Canada's scale. Keep sessions short and make sure kids have a place to go for regular indoor breaks to warm up.

Try short sessions outside with regular indoor warm-up breaks, and change out of wet clothes right away.

Source: Environment and Climate Change Canada; American Academy of Pediatrics. Sitter Rank guideline built from these sources.

Follow your school's, daycare's or local NWS office's rules, which may be stricter.

Play bands at a glance

  • Go outside (15°F (-9°C) and warmer): Dress for the weather: several thin layers, a hat, mittens or gloves, and waterproof boots.
  • Limit time outside (-15°F to 14°F (about -26 to -10°C)): Short sessions with regular indoor breaks to warm up. Change out of wet clothes right away.
  • Stay inside today (Colder than -15°F (about -26°C)): Indoor play. AAP: playing outside below -15°F should be avoided; exposed skin begins to freeze within minutes.

An active NWS Extreme Cold Warning means stay inside; a Cold Weather Advisory means at least limit time.

What to wear and what to watch for

A quick checklist for nannies, babysitters, and daycare staff. Copy it into a text for your sitter.

What to wear (AAP)

  • Several thin layers to keep kids warm and dry (AAP)
  • Insulated boots, mittens or gloves, and a hat are essential (AAP)
  • Change out of any wet clothes right away (AAP)
  • Set reasonable limits on time outside, with a place to go for regular indoor breaks to warm up (AAP)

Consider (Iowa HHS)

  • Dress in layers
  • Wear a hat and mittens
  • Waterproof boots
  • Communicate with parents about the need for appropriate clothing
  • Check equipment for safety (i.e., ice)

Watch for (Iowa HHS)

  • Paleness
  • Cold hands and feet
  • Sneezing more than usual
  • Very still and quiet
  • Crying or fussing more than usual
  • Shivering

Frostbite warning signs

  • Redness or pain in any skin area may be the first sign of frostbite (NWS)
  • A white or grayish-yellow skin area, skin that feels unusually firm or waxy, or numbness (NWS)
  • Skin may hurt or feel like it's burning, then quickly go numb; it may turn white or pale gray and form blisters (AAP)
  • Fingers, toes, ears, and noses are most likely to get frostbite (AAP)

Go to a hospital: if skin turns blue or gray, is very swollen, blistered or feels hard and numb even under the surface, go to a hospital as soon as possible (NWS).

Wind chill and frostbite chart (°F, wind in mph)

Each cell is the NWS wind chill for that air temperature (columns) and wind speed (rows). Shading uses Environment and Climate Change Canada's frostbite risk bands, not the NWS chart image. The outlined cell is closest to your input.

Wind chill in °F by air temperature in °F and wind speed in mph, with Environment Canada frostbite risk
Wind (mph) by air temperature (°F)4035302520151050-5-10-15-20-25-30-35-40-45
536No frostbite risk from cold31Low risk25Low risk19Low risk13Moderate risk7Moderate risk1Moderate risk-5Moderate risk-11Moderate risk-16Moderate risk-22High risk-28High risk-34High risk-40Very high risk-46Very high risk-52Very high risk-57Severe risk-63Severe risk
1034No frostbite risk from cold27Low risk21Low risk15Low risk9Moderate risk3Moderate risk-4Moderate risk-10Moderate risk-16Moderate risk-22High risk-28High risk-35High risk-41Very high risk-47Very high risk-53Very high risk-59Severe risk-66Severe risk-72Extreme risk
1532Low risk25Low risk19Low risk13Moderate risk6Moderate risk0Moderate risk-7Moderate risk, closest to your input-13Moderate risk-19High risk-26High risk-32High risk-39High risk-45Very high risk-51Very high risk-58Severe risk-64Severe risk-71Extreme risk-77Extreme risk
2030Low risk24Low risk17Low risk11Moderate risk4Moderate risk-2Moderate risk-9Moderate risk-15Moderate risk-22High risk-29High risk-35High risk-42Very high risk-48Very high risk-55Severe risk-61Severe risk-68Extreme risk-74Extreme risk-81Extreme risk
2529Low risk23Low risk16Low risk9Moderate risk3Moderate risk-4Moderate risk-11Moderate risk-17Moderate risk-24High risk-31High risk-37High risk-44Very high risk-51Very high risk-58Severe risk-64Severe risk-71Extreme risk-78Extreme risk-84Extreme risk
3028Low risk22Low risk15Moderate risk8Moderate risk1Moderate risk-5Moderate risk-12Moderate risk-19High risk-26High risk-33High risk-39Very high risk-46Very high risk-53Very high risk-60Severe risk-67Extreme risk-73Extreme risk-80Extreme risk-87Extreme risk
3528Low risk21Low risk14Moderate risk7Moderate risk0Moderate risk-7Moderate risk-14Moderate risk-21High risk-27High risk-34High risk-41Very high risk-48Very high risk-55Severe risk-62Severe risk-69Extreme risk-76Extreme risk-82Extreme risk-89Extreme risk
4027Low risk20Low risk13Moderate risk6Moderate risk-1Moderate risk-8Moderate risk-15Moderate risk-22High risk-29High risk-36High risk-43Very high risk-50Very high risk-57Severe risk-64Severe risk-71Extreme risk-78Extreme risk-84Extreme risk-91Extreme risk
4526Low risk19Low risk12Moderate risk5Moderate risk-2Moderate risk-9Moderate risk-16Moderate risk-23High risk-30High risk-37High risk-44Very high risk-51Very high risk-58Severe risk-65Severe risk-72Extreme risk-79Extreme risk-86Extreme risk-93Extreme risk
5026Low risk19Low risk12Moderate risk4Moderate risk-3Moderate risk-10Moderate risk-17Moderate risk-24High risk-31High risk-38High risk-45Very high risk-52Very high risk-60Severe risk-67Extreme risk-74Extreme risk-81Extreme risk-88Extreme risk-95Extreme risk
5525Low risk18Low risk11Moderate risk4Moderate risk-3Moderate risk-11Moderate risk-18High risk-25High risk-32High risk-39Very high risk-46Very high risk-54Severe risk-61Severe risk-68Extreme risk-75Extreme risk-82Extreme risk-89Extreme risk-97Extreme risk
6025Low risk17Low risk10Moderate risk3Moderate risk-4Moderate risk-11Moderate risk-19High risk-26High risk-33High risk-40Very high risk-48Very high risk-55Severe risk-62Severe risk-69Extreme risk-76Extreme risk-84Extreme risk-91Extreme risk-98Extreme risk

Frostbite risk legend (Environment and Climate Change Canada)

  • No frostbite risk from cold (above 0°C, above 32°F): When the temperature is above zero, there is no risk of frostbite no matter how windy it is.
  • Low risk (0 to -9°C, about 32 to 15°F): Slight increase in physical discomfort.
  • Moderate risk (-10 to -27°C, about 14 to -17°F): Physical discomfort. Risk of hypothermia and frostbite if outdoors for long periods of time without adequate protection.
  • High risk (-28 to -39°C, about -18 to -39°F): Any exposed skin can freeze in 10 to 30 minutes. Check your face and extremities for numbness or whiteness.
  • Very high risk (-40 to -47°C, about -40 to -53°F): Any exposed skin can freeze in 5 to 10 minutes.
  • Severe risk (-48 to -54°C, about -54 to -66°F): Exposed skin can freeze in 2 to 5 minutes.
  • Extreme risk (-55°C or colder, about -67°F or colder): Exposed skin can freeze in less than 2 minutes. DANGER! Outdoor conditions are hazardous.

In sustained winds over 50 km/h (about 31 mph), frostbite can occur faster than indicated.

Learn

How wind chill works

The NWS formula

Wind pulls heat away from exposed skin faster than still air, so it feels colder than the thermometer says. The National Weather Service calculates it as:

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 at the national standard height of 33 feet, the typical height of an anemometer, so ordinary forecast winds are the right input. Wind chill is only defined at or below 50°F and at wind speeds above 3 mph. Bright sunshine may increase the wind chill temperature by 10°F to 18°F, but sun is not part of the formula.

Worked example

If the temperature is 0°F and the wind is blowing at 15 mph, V^0.16 is about 1.543, so the wind chill is 35.74 + 0 - 35.75 × 1.543 + 0 ≈ -19°F. The National Weather Service says that at this wind chill, exposed skin can freeze in 30 minutes.

-19°F is about -28°C, the start of Environment Canada's high risk band, where any exposed skin can freeze in 10 to 30 minutes. It is also below the AAP's -15°F line, so this tool says to keep kids inside. Frostbite can happen in minutes, especially on fingers, toes, nose and ears. When body temperature sinks below 95°F, it is hypothermia.

Common questions

Wind chill and frostbite FAQ

How is wind chill calculated?

The National Weather Service formula is: wind chill (°F) = 35.74 + 0.6215T - 35.75(V^0.16) + 0.4275T(V^0.16), where T is the air temperature in °F and V is the wind speed in mph at the national standard height of 33 feet, the typical height of an anemometer. Wind chill is only defined for temperatures at or below 50°F and wind speeds above 3 mph. For Celsius, convert to °F and mph (1 mph = 1.609344 km/h), apply the formula, and convert back.

What wind chill causes frostbite, and how fast?

Environment and Climate Change Canada says any exposed skin can freeze in 10 to 30 minutes at wind chills of -28 to -39°C (about -18 to -39°F), in 5 to 10 minutes at -40 to -47°C, in 2 to 5 minutes at -48 to -54°C, and in less than 2 minutes at -55°C or colder. In sustained winds over 50 km/h, frostbite can occur faster than indicated. The National Weather Service example: at 0°F with a 15 mph wind, the wind chill is -19°F and exposed skin can freeze in 30 minutes.

How cold is too cold for kids to play outside?

The American Academy of Pediatrics says playing outside in temperatures or wind chills below -15°F should be avoided, because exposed skin begins to freeze within minutes. In moderate-risk cold, set reasonable limits on time outside and make sure kids have a place to go for regular indoor breaks to warm up. Always follow your school's, daycare's, or local NWS office's rules, which may be stricter.

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

On October 1, 2024, the National Weather Service renamed Wind Chill Warnings to Extreme Cold Warnings, Wind Chill Watches to Extreme Cold Watches, and Wind Chill Advisories to Cold Weather Advisories, to clarify that cold can be dangerous with or without wind. A warning is the more severe of the two. Criteria are set locally by each NWS office, so there is no single national threshold. For example, NWS Rochester, NY uses an Extreme Cold Warning at or below -25°F and a Cold Weather Advisory from -15°F to -24°F.

What should kids wear to play in the cold?

The AAP recommends several thin layers to keep kids warm and dry, and says insulated boots, mittens or gloves, and a hat are essential. Change children out of any wet clothes right away. Children are more at risk from the cold than adults, because their smaller bodies lose heat more quickly.

Sources

All formulas, bands, and safety wording come from these pages, checked October 29, 2026. The go, limit, and stay-inside bands are Sitter Rank's guideline built from these sources, not an official standard. This tool is not medical advice.

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