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OPO to ISN: distance & flight time
Porto (Francisco de Sá Carneiro Airport) → Williston (Sloulin Field International Airport)
4,380 mi
7,048 km · 3,806 nm
9h 3m
estimated nonstop flight time
-6h
time difference · heading northwest
See live OPO→ISN fares Phone-only fares on this route — call free
Flight time details
4,380 miles nonstop takes roughly 9h 3m gate to gate, flying northwest. Add 45–90 minutes per connection if there's no nonstop service. Remember to factor the 6-hour time set-back when reading arrival times on your ticket.
The two airports
- OPO — Francisco de Sá Carneiro Airport · Porto, Portugal
- 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 OPO
- BGZ · Braga Municipal Aerodrome26 mi away
- VRL · Vila Real Airport50 mi away
- VSE · Aerodromo Goncalves Lobato (Viseu Airport)55 mi away
- VGO · Vigo Airport68 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 OPO from ISN?
The flight distance from Porto (OPO) to Williston (ISN) is 4,380 miles (7,048 km, 3,806 nautical miles), measured along the great-circle route airlines actually fly.
How long is the flight from OPO to ISN?
A nonstop flight takes about 9h 3m 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 Porto and Williston?
Williston is 6 hours behind Porto.
What is the cheapest way to fly from OPO to ISN?
Compare live fares online, then call CheapoTrav — our agents have unpublished consolidator fares on OPO–ISN that never appear on search engines, with no booking fees.