Cycling jackets are a great choice for colder days. They are made of windproof material, so they protect the rider against cold wind, and the extended back part of the jacket prevents water from getting under it. It is an indispensable element of a cyclist's equipment for winter – thanks to it, it is possible to ride a bike comfortably even in low temperatures.
When choosing a cycling jacket, you must remember that it cannot be too tight-fitting. When dressing for a bike on colder days, you must remember about the principle of wearing layers. So the more layers the better. It's easier to take one off and put it in a pocket than to wear not enough garments.
A separate category are lightweight cycling jackets that protect against rain. They are most often made of waterproof material, and when folded, they can even fit into a seat bag. It's worth having it there for a rainy day - you never know when bad weather may surprise you.