How many feet before a turn should you signal?

100 feet or 4 seconds ferore the turn but when it's like raining or anything like that 200 feet. It gives people behind time to think if their paying attention.

To maximise safety, it is best to signal for at least three seconds before you make a turn (this is a legal requirement on New Zealand roads).

In the UK there is no specific distance. The signal should be clear and unambiguous and suit local conditions.