A quality jacket is essential for year-round riding.
Throughout the summer, a thin, packable showerproof jacket is useful to store in a jersey pocket for unexpected showers. Similarly, for early starts, a windproof gilet is ideal to keep the chill off, without creating too much bulk. On cold, winter rides, a highly waterproof and windproof jacket will keep you warm and dry, yet with a high level of breathability, you won't find yourself over heating.