The wind chill factor is a temperature that represents the “feels like” temperature of wind on exposed skin in terms of an equivalent temperature in calm conditions. Wind speed is the most important factor in calculating wind chill, but humidity and pressure are also sometimes included. The wind chill effect arises because as wind blows over the skin, it evaporates moisture, leading to a cooling effect.
Wind chill factors are generally only considered for temperatures below 20C. Examples of some wind chill factors are:
20C with no wind = 20C wind chill
20C with 30kph wind = 15C wind chill
15C with 20kph wind = 10C wind chill
15C with 60kph wind = 5C wind chill
5C with 60kph wind = -10C wind chill
0C with 40kph wind = -15C wind chill
Wind chill is not an exact measurement. Direct sunlight can provide some warming effect to counteract it. Different people may feel wind chill in different ways, such as thin people who will lose heat faster than larger people. However, it is a useful measurement. Wind chill below -50C can lead to unconsciousness and eventually death. Generally, in Australian conditions, wind chill factors will not fall far below -15C as seen above. While this may be unpleasant, it will have no impact generally on human health.
20:14 EST As the sun set over Melbourne, a thick fog engulfed the city.