Blue hour is not an hour

The photographers borrowed the term and made it sound tidy. It is not tidy. Blue hour is whatever stretch of time the sun spends just far enough below the horizon to light the sky without lighting the ground, and at this latitude that quantity swings wildly.

In late December the whole day can feel like a long slow dusk that never fully committed. In June there is a week where it does not properly arrive, and the sky just dims slightly, like someone leaning on a switch and changing their mind.

What to do with it

Walk in it. Snow returns the blue upward, which is why a field at four in the afternoon in January looks lit from underneath. Nothing you photograph will look the way it does in person, and that is fine, that is arguably the point.