Non-stop flights are operated to Heathrow from Cologne and the journey will take around one hour and thirty minutes. Costs are minimal if booked in advance and if peak travel times are avoided.
The climatic conditions in London do not tend to differ much from those in Cologne - so a trip is always possible. Summers can be wet. It is always a good idea to pack an umbrella.
There are a number of local events which will make visiting the capital city particularly enjoyable: Notting Hill Carnival in August (Bank Holiday), Chinese New Year in Chinatown and Soho (usually at the beginning of February) or the Boat race in April are just a few of these.
Bear in mind that the currency used in the United Kingdom is the pound. Cashpoints are available at the airport - charges will depend on the type of card used to make the withdrawal.
Think before hiring a car if you are expecting to stay in Central London: there is a congestion charge for private motor vehicles if entering the central London area, which amounts to just under £12 a day.
There are many onward travel options once you have landed at London Heathrow. Taking the tube is by far the cheapest way of getting into the city centre. Piccadilly line trains stop at all Heathrow airport terminals. Heathrow Express trains are the quickest way of reaching central London. There are also trains, buses and coaches to many other destinations in the home counties.