Temperature and Real Feel
The "feels like" temperature (also known as apparent temperature) takes into account wind speed, humidity, and other factors that affect how temperature actually feels to your body.
Humidity Impact
High humidity (above 60%) reduces your body's ability to cool itself through sweat evaporation, making hot temperatures feel even hotter. This is why a 30°C day with high humidity can feel more uncomfortable than a 35°C day with low humidity.
The heat index formula accounts for this by combining temperature and humidity to calculate how hot it actually feels to the human body.
Wind Chill Factor
In cold weather, wind removes the thin insulating layer of warm air that surrounds your body. This increases the rate of heat loss, making it feel colder than the actual temperature.
The wind chill formula calculates how cold the air feels based on the actual temperature and wind speed. Wind chill only has a significant effect at temperatures below 10°C and wind speeds above 10 km/h.
UV Index
UV index measures the strength of ultraviolet radiation from the sun:
- 0-2: Low risk
- 3-5: Moderate risk - wear sunscreen
- 6-7: High risk - wear sunscreen and protective clothing
- 8-10: Very high risk - minimize sun exposure
- 11+: Extreme risk - avoid sun exposure
While UV doesn't affect the "feels like" temperature directly, it's an important factor for outdoor comfort and safety.
Temperature Perception Range
A 1°C difference in temperature is generally noticeable to humans. When the "feels like" temperature differs from the actual temperature by:
- 0-1°C: Barely noticeable
- 1-3°C: Slightly different from thermometer
- 3-6°C: Noticeably different from thermometer
- 6°C+: Significantly different from thermometer