I'm trying to decide on a possible train/car route in northern norway sometime in august 2025. Lofoten Islands of course on our list (and will be visiting Svalbard). Not sure how much time we'll spend yet as the Svalbard piece isn't set yet. Possible hiking may be in the mix, yet again not sure yet. If you're willing to share your thoughts it would be much appreciated.
There are no trains in northern Norway, only rail network ends Bodø and Narvik.
Buses, ships and cars are the options. For cars have a look at the Norwegian scenic routes.
August is between months for nature experiences Northern Lights and Midnight Sun. For experiencing one of both you might change month of travel.
Consider Hurtigruten or Havila journeys (e. g. port-to-port) for getting along the beautiful coastal route.
North Cape and Tromsø are typical tourist destinations in that area.