Why is it warm when it snows and cold when it melts?

That's because there are clouds in the sky when it snows, which prevents the big flow of air and reduces the radiation on the ground. It will feel colder than usual.

When melting snow, the weather is often sunny, and it is often accompanied by dry and cold winds. This kind of weather itself is cold, and the ice and snow change from solid to liquid, so it needs to absorb heat from the air, resulting in a lower temperature than normal, so it will feel cold.

Extended data:

Reasons for the formation of snow:

One condition is that water vapor is saturated. The maximum amount of water vapor that air can hold at a certain temperature is called saturated water vapor. The temperature at which air reaches saturation is called dew point. When saturated air is cooled to a temperature below the dew point, the excess water vapor in the air becomes water droplets or ice crystals.

Another condition is that there must be condensation nuclei in the air; Condensation nuclei are tiny solid particles suspended in the air. The ideal condensation nuclei are those particles that absorb the most water.

Such as sea salt, sulfuric acid, nitrogen and other chemicals. So we sometimes see clouds in the sky, but there is no snow. In this case, people often use artificial snowfall.