The distance between Delhi and Lahaul Spiti is 712 Kilometers. There are no airports on the route that you take while traveling to Spiti. You're recommended to take flights from wherever you are coming to Delhi only. After that, you need to move on the road in a 4x4 car or tempo traveler. If you think that the distance between Delhi to Spiti valley is way too much for you in terms of a road trip then you can land in Chandigarh which is a little closer to Spiti Valley and will shorten your road trip by a couple of hours.