What Time Is Blue Hour?
Blue hour is not a fixed clock time. It follows sunrise and sunset, so the best answer comes from calculating it for your location and date.
When blue hour happens
Morning blue hour happens before sunrise. Evening blue hour happens after sunset. In practical photography planning, it is the time when the sun sits below the horizon and the sky turns a rich blue.
A common rule of thumb is 20 to 40 minutes, but the real timing can be shorter or longer depending on where you are.
Why the time changes
Blue hour changes because the sun's angle changes through the year. Your latitude also matters: locations farther from the equator often have longer twilight periods.
Planning tip
If you are photographing landscapes or cityscapes, check the evening blue hour first. For quiet streets, reflections, or dawn landscapes, the morning blue hour can be even better.