A jacket can be worn when cold winds pester your running route. Jackets offer protection from the wind, and most jackets are also water repellent.
Some jackets have hoodies for extra protection. Gore's ShakeDry Run jacket is even completely waterproof, but also breathable, lightweight and comfortable.
For colder conditions the Base Warm Up jackets of Newline are perfect. These jackets are made of fleece material and are perfectly suitable for runs on cold winter days in temperatures of -15°C to 0°C.
A jacket usually forms your top layer in winter. Many jackets therefore have reflective elements, so you can run safely in low-light conditions.