Why does it
feel so cold?

When it's cold out, we lose body heat. This heat is absorbed by the air that surrounds us.

On calm days, the heat lost from our bodies forms a thin layer of warm air along the surface of our bodies. This warm layer of air acts as an insulator against the colder air around us.

As the wind starts to blow, our layer of warm insulating air gets swept away and our skin is exposed directly to the cold air. Any new heat we give off is carried away with the wind.

The more wind there is, the quicker we lose heat.

Wind does not change the temperature of the air. If a thermometer is placed outside, it will read the same temperature regardless of whether it's a windy day or a calm day.

It simply "feels" colder because the heat that we give off is immediately blown away.