London, with countless famous sites and all manner of food, drink, shopping, history, and culture, is definitely a wonderful city to visit.
Time Zone
Greenwich Mean Time during the winter, British Summer Time during the rest of the year (starting at Daylight Saving Time).
Best Time to Go
The best time to visit London overall is in spring, when the temperatures have warmed up, the sun has started to shine and London's gardens and parks are looking their best. However, the reality is that the best time to travel to London depends a lot on what you're looking for. If you're all about taking a look inside Queen Liz's palace, you'd better make it in summer, while winter is beautiful and festive for those looking to get their fill of Christmas markets and traditional cheer.
Things to Know
Londoners, and English people in general, have a much different manner of interacting with one another than Americans do while an American might think nothing of smiling at a stranger they pass on the sidewalk or asking about work in the first few minutes of a conversation,
Londoners might consider it impolite or strange. Don't mistake this for unfriendliness; it's just a cultural difference. Instead, talk about things like movies, TV shows, books, your travels, and the like, instead of work or family.
How to Get Around
Getting around London is unbelievably easy thanks to the well-maintained and extensive Underground. The Underground, unlike American transportation systems which often pay per ride or pay per length of trip, are paid in zones. Fare also varies based on time of day and the method you use to pay. It's worth getting an Oyster card to make your life that much simpler.