When is the golden hour and the blue hour at your location? See the exact morning and evening windows — and why they last longer the further north you go.
The golden hour and the blue hour are the two best light windows of the day, and both are defined purely by the sun's altitude. That means they can be calculated exactly rather than forecast. The times above are for the location you have selected.
The golden hour is the period when the sun sits between roughly 6° above the horizon and sunset itself — and mirrored in the morning, from sunrise up to 6°. The light passes through so much atmosphere that the short blue wavelengths are scattered out of the path, and what arrives is warm, soft and directional, with long shadows.
The blue hour sits just outside it, when the sun is between 4° and 6° below the horizon. The direct light is gone but the upper atmosphere is still lit, and because the long wavelengths are now filtered out, the sky turns a deep, even blue.
Both names are inaccurate. Neither lasts an hour. In London the golden hour runs between 44 and 62 minutes depending on the season and the blue hour between 13 and 20; in Copenhagen, 49 to 78 and 14 to 26. Both get shorter the closer you are to the equator: in Singapore the golden hour is about half an hour and the blue hour under ten minutes, all year.
The golden hour produces light that is hard to recreate: low, warm and soft enough that faces do not pick up hard shadows, yet still directional enough to give shape and depth. It is the only time of day you get both at once.
The blue hour solves a different problem. It is the brief window in which artificial lighting and the sky are close enough in brightness for a camera to expose for both at the same time. Wait until it is properly dark and the windows become white holes in a black field. This is why almost every good photograph of a city "at night" was in fact taken during the blue hour.
What sets the duration is the angle at which the sun crosses the horizon. Near the equator it drops almost vertically and passes through those few degrees quickly. At high latitudes it slides sideways at a shallow angle and takes far longer to sink the same number of degrees.
The difference is large. In Singapore the whole transition from sunset to darkness is over in a little more than 20 minutes. In London it takes 33 minutes at the equinoxes and 48 in June; in Copenhagen 37 and 61; in Oslo 41 and over 100.
Both windows are shortest at the equinoxes. That is when the sun rises due east and sets due west and crosses the horizon at the steepest angle it ever manages for a given latitude, so it ploughs through those few degrees quickly. At either solstice its path is tilted further from vertical and the light drags out.
From there the two diverge, and this is the part almost no calculator explains. The blue hour is longest in summer — 20 minutes in London against 13 at the equinox — because in June the sun travels almost parallel to the horizon while it is a few degrees below it.
The golden hour, by contrast, is longest in winter. In London it lasts 62 minutes at the December solstice against 54 in June, and in Copenhagen 78 against 64. The reason is that the golden hour sits above the horizon, between 0° and 6°, and at midwinter the sun barely reaches 11° at all. It crawls through that band rather than crossing it. This is the physical reason northern winter light looks the way it does: a large share of the short day is genuinely golden hour.
Rarely an hour. In London it varies from 44 minutes around the equinoxes to 62 at the December solstice, and in Copenhagen from 49 to 78 — longest in winter, because the sun barely climbs above 6° at all. Near the equator it drops to around half an hour.
The golden hour happens while the sun is still up, between roughly 6° above the horizon and sunset, and the light is warm and soft. The blue hour follows sunset, when the sun is 4–6° below the horizon and the sky turns deep blue.
In the part of the window where street lighting and the sky are about equal in brightness. That typically falls 15–25 minutes after sunset, which is why it pays to stay put for a while once the sun has gone.