It might be cold out and it’s going to get colder, but once you’re cycling you’re going to warm up, so you need a versatile jacket that’s not too heavy and is going to work for wet weather as well. Don’t dress too warmly, go with a lightweight wind resistant shell as your outer later with a zip front for venting. Wiggle has a selection for men and women including reflective jackets.
Once you’ve got the outer layer cracked, you want something light but insulating on the inside that will keep moisture off the skin. Vests are a good option as they warm your core while keeping your arms free. You can always add an easy to shed mid layer, but of course there are so many brilliant fabrics about now that keep your body temperature stable that you really are spoiled for choice. A personal favourite is Under Armour.
Cycling shorts and trousers
Unless you’re extremely hardy, it’s getting to the time to swap shorts for capris or full length tights. Breathable tights that have wind-resistant fronts are the best, but if they don't have padded bottoms (which they often don't), wear them over your cycling shorts. Cycling Weekly recommends a particularly sexy collection of ‘bibknickers’ or ‘bib tights’.
Vents seem like such a good idea when it’s hot outside, but in the middle of winter, particularly if it’s freezing, cold you may well think otherwise. Synthetic skullcaps and head bands worn under your helmet are the perfect solution, and if the temperature really drops and you choose one with ear flaps or a thin balaclava to it then it has the added benefit of making you look like a superhero. Halfords has a particularly comprehensive collection available.
Lights are important for any time of the year as you can never be 100% sure what visibility will be like. You can however guarantee that it will be worse in winter, so now’s the time to make sure you’re stocked up on lights and reflectors. Place a white light on the front of your bike and a red one (usually a flasher) in the rear, and make sure that your outer layer of clothing is reflective. They are often sold as a set, and as with so many things, Amazon has a particularly good collection to choose from.