The cheapest times to fly from PDX to ISN are

  • April 9th to April 29th
  • August 13th to September 9th
  • October 8th to November 4th
  • December 24th to March 4th

based on data collected exclusively by Champion Traveler across tens of millions of flights. Among all the dates above, the very cheapest time to fly from PDX to ISN is late January. Prices can be as high as $1021 for Monday flights during mid March, or as low as $242 for Saturday flights around late January.


When to Fly to Williston

Flying from Portland, OR (PDX) to Williston, ND (ISN) will usually cost between $368 to $825 per person if booking more than four weeks in advance. On average the very cheapest time to fly is late January with an average ticket price of $429. Due to high demand the most expensive time to fly is mid March, with an average price of $765. Planning your trip to low-cost times can easily save you $336 on economy flights and even more on first-class flights. Generally, any price below $603 can be considered a good price for a round-trip PDX to ISN flight.

See below for a graph of average weekly prices for the PDX to ISN route. All prices are for round-trip tickets in USD.

PDX to ISN Flight Prices

Compared to other flights, the PDX to ISN flight is cheaper than the average and costs less than the average flight leaving from Portland. The average price per mile (for a direct flight) is $0.41, which is a bit above average.


Flight Prices by Day of the Week

Saturday is usually the cheapest day to depart and return on this flight. Mondays are the most expensive days to fly out or take a return trip. Selecting flights on the least expensive days could save you up to $209 (29%) on this flight.

Departing prices are for round-trip flights returning on the day of departure. For example, a flight departing on Saturday and returning a week later will cost an average of $507. Return trip prices are from the ISN to PDX flight, and often highlight the quality of our data in showing the same trend.

Departing Prices by Day

Departure Day Prices

Return Trip Prices by Day

Return Day Prices


Nonstop Flights and Layovers

Travelers looking to fly from PDX to ISN can generally find a 1-layover flight. Because there is not usually a direct flight option the real-world direct flight time of 2 hour 37 minutes may not be realistic.


Alternative Nearby Airports

Champion Traveler tells you which airports are nearby and whether tickets might be cheaper alternative airports nearby. Sometimes it’s worth it to fly into a closer airport and then commute to your destination. Remember that there is not usually a nonstop flight from PDX to ISN while comparing.

Destination alternative #1: Minot International Airport (MOT) in Minot, ND

  • 109 miles (175 km) away from ISN
  • Usually 24.21% less expensive than ISN
  • 1-layover flights available

See PDX to MOT flights


Flight Questions Answered

Still have questions about flying from PDX to ISN? We’ve got answers.

Which airlines fly this route?

You can find 3 major airlines flying this route most often: Alaska, Delta, United, and potentially more during busy seasons.

How far away is it from Sloulin Field International Airport to Portland International Airport?

The distance between the two airports is roughly 910 miles or 1464 kilometers.

How long does it take to fly from PDX to ISN?

The real-world flight time for a nonstop PDX to ISN flight is about 2 hour 37 minutes.

How many flights go between Portland, OR and Williston, ND?

It depends on the day of the week and the date, but a typical day might have around 63 available flights from PDX to ISN.


Airport Location Info


Departing Airport

Origination codePDX
Origination airport namePortland International Airport
CityPortland, OR
Countrythe United States

Return Airport

Destination codeISN
Destination airport nameSloulin Field International Airport
CityWilliston, ND
Countrythe United States


Other Resources

Please note that while we’ve worked hard to analyzed tens of millions of flights to get you this data, we do not calculate current live prices or guarantee pricing. Please see our partners using the links above for current offers.