It depends when exactly in winter and where exactly in Britain. However, it will definitely be cold, wet and grey. There may well be snow or sleet. The temperatures are often below freezing at night but not often that cold during the day. However, it is very, very wet in Britain so it feels much colder than it actually is. The daylight hours are short, especially further north. I'd wait 'til spring if I were you. ;-)

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