Air, as it travels, tends to maintain many of the properties it had at the source in transit. That is why a southerly wind from the Gulf of Mexico is warm when it blows through the arch in St. Louis and a northerly wind is cold when it blows down Michigan Avenue in Chicago. However, air is slowly modified enroute. The cold air is warmed by contact with the warm surface and is less cold by the time it reaches Jacksonville, Florida. The warm air loses some of its warmth and moisture through radiational cooling and condensation before it reaches Boston.
Winds change direction and speed constantly as weather features move and change strength.
Winds also tend to increase with height. Winds outside of hurricanes, tornadoes and strong winter storms usually average less than 20 mph at the surface. This is called the jet stream. The winds here are strongest in regions where the temperature contrast in lower levels is strongest. That is usually along what is known as the polar front, the boundary between cold polar air and warm tropical air.