Every nonstop to Hawaii, and what the wind costs you

The extra time grows faster than the distance

That flying west takes longer is not news. What surprised me is that the extra time does not stay proportional to the distance. The longer the route, the bigger that gap becomes as a share of the return flight.

One route per airport below, the Honolulu one, so the rows compare like with like. The ranked table further down averages every route an airport flies, which is why a few numbers differ between the two.

San Francisco gives up about 8 percent of its return time. Newark gives up 17.5 percent over roughly twice the distance. Across the 66 westbound pairs the extra time tracks distance at r = 0.94 with a negative intercept.

That is a strong trend and it is not a rule. Seattle is the row that makes that clear. It is 121 miles further out than Los Angeles and gives up three minutes less. Whatever is happening is not simply a function of distance.

I do not know why

The obvious guess is the jet stream, and that the longer routes spend more of the flight in the stronger part of it. That makes sense until you notice Seattle is the northernmost departure in the table and one of the smallest gaps, so the explanation does not survive its own example.

The DOT data gives me flight times and distances, not winds aloft. I cannot settle the question from this dataset and I am not going to pretend I can. If you have historical winds-aloft data that would let me test it, I would like to see it.

Why the two on the far side are not exceptions

The jet stream generally runs west to east across the Pacific. Fly west into it and it costs you time. Fly east with it and it gives some back.

For a while this page said 66 of 68 routes, with two exceptions. That is technically true and it makes the two routes sound mysterious. They are Guam and Pago Pago. Both are west and south of Hawaii, so flying from either one to Hawaii means flying east, and both are faster flying out, Guam by 37 minutes and Pago Pago by 16.

Once you account for direction it is 68 out of 68. Every route that flies west to reach Hawaii is slower doing it. Both routes that fly east to reach Hawaii are faster.

The map is what made this obvious. Each airport is placed by its initial great-circle bearing from Honolulu rather than on a conventional geographic map, so Guam and Pago Pago land on the opposite side of the circle from everything else and the colour flips there too.