Air Temperature vs Feels Like
A thermometer measures the temperature of the air. Your body responds to more than that number. Wind changes how quickly you lose heat, humidity affects how readily sweat evaporates, and sunshine adds radiant heat. This is why the temperature on a forecast can differ from the feels like value.
There is no single calculation for every situation. In cold weather, forecasts commonly use wind chill. In hot, humid weather, they commonly use the heat index. Both are estimates of how conditions affect the human body, not a different measurement of the air itself.
Wind Chill
Your skin warms a thin layer of air next to your body. Moving air replaces that layer with colder air, increasing heat loss from exposed skin. Stronger wind usually makes cold conditions feel harsher, which is why wind speed matters as much as temperature on some winter days.
The standard wind chill index is defined for air temperatures at or below about 10°C (50°F) and wind speeds above roughly 5 km/h (3 mph). These are limits of the formula, not limits of physics. Above 10°C, wind can still cool your body through convection and by helping sweat evaporate. Forecasters simply do not describe that effect with the standard wind chill index.
Air temperature Wind speed Feels like 0°C (32°F) 10 km/h (6 mph) -3°C (27°F) 0°C (32°F) 30 km/h (19 mph) -7°C (19°F) -10°C (14°F) 10 km/h (6 mph) -15°C (5°F) -10°C (14°F) 30 km/h (19 mph) -20°C (-4°F)The values in the table are rounded examples for exposed skin. At very low wind chills, frostbite can develop quickly, but published frostbite times are estimates rather than personal countdowns. Cover exposed skin, wear dry layers, and seek shelter if skin becomes numb, pale, waxy or painful. Hypothermia can also occur without frostbite, especially after prolonged exposure or when clothing is wet.
Heat Index
Sweat cools your body when it evaporates. When the air is humid, evaporation slows and your body has more difficulty shedding heat. The heat index combines air temperature and relative humidity to estimate how hot those conditions feel. If you want to understand why the same temperature can feel different from one day to the next, read our guide to humidity and dew point.
Air temperature Relative humidity Feels like 30°C (86°F) 40% 30°C (86°F) 30°C (86°F) 70% 35°C (95°F) 35°C (95°F) 40% 37°C (99°F) 35°C (95°F) 70% 50°C (122°F)Standard heat-index values assume shade and light wind. Direct sunshine adds radiant heat that the index does not fully represent, while strong wind in very hot, dry conditions can also increase heat stress. Treat the forecast value as a guide, then consider whether you will be in the sun, exercising or working outdoors.
There is no sharp line below which heat is safe for everyone. Risk rises with the apparent temperature, the length and intensity of exposure, and personal factors such as age, health, medication and acclimatisation. Heat exhaustion and heatstroke can occur during prolonged exposure or physical activity. Move to a cooler place and seek urgent medical help if someone becomes confused, collapses or loses consciousness.
Why the Difference Matters
A cold day at -5°C (23°F) with strong wind can feel closer to -15°C (5°F) on exposed skin. A humid afternoon at 32°C (90°F) can produce a heat index near 42°C (108°F). Looking only at air temperature can leave you underprepared for either situation.
When wind is light and humidity is not interfering much with evaporation, air temperature and feels like temperature may be close. That does not make either value more “real”. They answer different questions: one describes the air, while the other estimates how the conditions affect your body.
What the Number Cannot Tell You
Feels like temperature is based on a standard model, so it cannot describe every person’s experience. Your exposure also matters:
- Sun and shade: Air temperature is measured in shaded, ventilated conditions. Direct sun adds radiant heat.
- Clothing: Wind-resistant outer layers reduce the direct effect of wind, while breathable clothing can help sweat evaporate in warm weather.
- Activity: Movement generates body heat. It may make a cool day feel comfortable but increases strain in hot conditions.
- Wet skin and clothing: Water can speed heat loss in cold weather.
- Personal factors: Age, health, medication and acclimatisation all affect heat and cold risk.
Because these factors differ, use feels like temperature as a planning tool rather than a precise description of how every person will feel.
How Airpult Shows Feels Like Temperature
Airpult shows the feels like value beside the forecast air temperature. When the two differ, check the wind, humidity and weather conditions before deciding what to wear or how long to stay outside. Use the explore page to find a location and see its latest forecast.
