You shouldnâ€t just go outside with a tank top and waterproof jacket over the top and call it a day. Well, you could, but donâ€t expect yourself to be very comfortable. You want to layer to combine various layers of clothing to ensure youâ€re properly protected and comfortable in the wind and rain.
Various thin layers as opposed to just one bulky layer can help keep you warmer, as the multiple layers trap heat and act as an insulator. You can also more effectively regulate your temperature as you go by adding and removing layers, depending on how you feel.