We would love to give you an exact statistical answer to this most asked question but the truth is that we simply cannot say.
The Northern Lights are Mother Nature's creation and as such we can't even use historical data to predict how likely you are to witness a display. The Sun's activity varies, cloud cover varies, solar winds vary and these and other factors can all influence the likelihood of seeing the Aurora. Indeed, accurately predicting an Auroral display is only possible a few hours at best before it happens because the interaction of solar wind with the Earth's magnetic field is crucial. So, while we may know that the Sun has thrown a Coronal Mass Ejection our way, we don't know how it will react when it reaches us.
What we do at The Aurora Zone is seek to maximise your chances of seeing an Aurora. There are certain ways of doing this which we have discussed elsewhere but you can help yourself too. It is no coincidence that persistence and vigilance pay dividends and this can mean some seriously late nights. We will take you out during the peak hours of roughly 9pm and 1am (this may vary according to local conditions and/or Auroral forecasts) but the Northern Lights are fickle and we can't simply turn them on with the flick of a switch.
Hence, if they don't appear before we return you to your warm accommodation, you may wish to stay out longer, perhaps somewhere sheltered down by a lake where you'll often find others have gathered for the same purpose. If Lady Aurora decides to stay wrapped up warm in front of the fire, if nothing else, you'll all have a jolly good laugh and make some new friends.