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PSM to ISN: distance & flight time
Portsmouth (Portsmouth International at Pease Airport) → Williston (Sloulin Field International Airport)
1,611 mi
2,593 km · 1,400 nm
3h 38m
estimated nonstop flight time
-1h
time difference · heading northwest
See live PSM→ISN fares Phone-only fares on this route — call free
Flight time details
1,611 miles nonstop takes roughly 3h 38m gate to gate, flying northwest. Add 45–90 minutes per connection if there's no nonstop service. Remember to factor the 1-hour time set-back when reading arrival times on your ticket.
The two airports
- PSM — Portsmouth International at Pease Airport · Portsmouth, United States
- ISN — Sloulin Field International Airport · Williston, United States
Distances are great-circle ("as the crow flies") — the same basis airlines use for frequent-flyer miles.
Alternate airports can cut this fare
Flying from or into a nearby airport is the #1 trick our agents use to beat online prices. Call and we'll compare every combination on one call.
Near PSM
- BOS · General Edward Lawrence Logan International Airport50 mi away
- LWM · Lawrence Municipal Airport29 mi away
- MHT · Manchester-Boston Regional Airport33 mi away
- BVY · Beverly Municipal Airport34 mi away
Near ISN
- SDY · Sidney - Richland Regional Airport41 mi away
- YEN · Estevan Airport78 mi away
- OLF · L M Clayton Airport89 mi away
- GDV · Dawson Community Airport90 mi away
Frequently asked questions
How far is PSM from ISN?
The flight distance from Portsmouth (PSM) to Williston (ISN) is 1,611 miles (2,593 km, 1,400 nautical miles), measured along the great-circle route airlines actually fly.
How long is the flight from PSM to ISN?
A nonstop flight takes about 3h 38m gate to gate. Actual time varies with winds, routing and season — eastbound transatlantic flights, for example, are usually faster than the return.
What is the time difference between Portsmouth and Williston?
Williston is 1 hour behind Portsmouth.
What is the cheapest way to fly from PSM to ISN?
Compare live fares online, then call CheapoTrav — our agents have unpublished consolidator fares on PSM–ISN that never appear on search engines, with no booking fees.