What is blue hour?
Blue hour is one of the most magical times of day for photographers, city explorers, and anyone who loves a moody sky. But what exactly is blue hour, when does it occur, and how can you make the most of it? In this comprehensive guide, we’ll break down the science, the timing, and the best tips for capturing that signature deep-blue twilight.
What Is Blue Hour? A Simple Definition
Blue hour is the period of twilight, just before sunrise and just after sunset, when the sun is well below the horizon and the remaining indirect sunlight takes on a deep, even blue tone. Unlike the warm, golden glow of golden hour, blue hour bathes the sky in cool, soft blues and purples. It’s a favourite for cityscapes because artificial lights balance beautifully against the still-luminous sky.
The colour comes from how the atmosphere filters sunlight when the sun is below the horizon: longer red wavelengths pass out into space while shorter blue wavelengths scatter down toward the ground. This is the same reason the sky is blue during the day, but during blue hour, the effect is more concentrated and dramatic. For a deeper dive into the mechanics, read about the science of sunrise.
When Does Blue Hour Happen?
In the evening, blue hour runs from just after sunset until the end of civil twilight. In the morning, the sequence reverses: blue hour begins when civil twilight starts and ends just before sunrise. The exact timing depends on your location and the time of year. For instance, blue hour lasts longer in winter and is shorter near the equator. Every city page on sunset.now lists today’s evening and morning blue hour windows, so you can plan your shoot with precision.
If you’re wondering how latitude affects the duration, check out how-latitude-affects-sunset-times. In general, the farther you are from the equator, the longer blue hour lasts, especially around the solstices. For example, in Chicago, blue hour can stretch to nearly 40 minutes in winter, while near the equator it may last only 20 minutes.
Blue Hour vs. Golden Hour: What’s the Difference?
The key difference is colour and timing. Golden hour is the warm, soft light just after sunrise and just before sunset, when the sun is low but still above the horizon. Blue hour follows in the evening (and precedes in the morning), occurring when the sun is 4–18 degrees below the horizon. In the evening, golden hour comes first, then blue hour follows. In the morning, the order reverses. See golden hour vs blue hour for a side-by-side comparison.
Golden hour gives you warm oranges and yellows, while blue hour offers cool blues and purples. Both are popular for photography, but blue hour is especially prized for urban nightscapes because the sky still has some luminance that balances perfectly with streetlights and building windows. If you’re trying to decide which to use for a shoot, consider your subject: landscapes often shine in golden hour, while cityscapes and moody portraits thrive in blue hour.
How Long Does Blue Hour Last?
Blue hour typically lasts 20 to 40 minutes, depending on your latitude and the season. It begins at the end of civil twilight (when the sun is 6 degrees below the horizon) and ends at the start of nautical twilight (when the sun is 12 degrees below). In the morning, it’s the reverse. For a full breakdown of twilight phases, read twilight-explained. To get precise times for your location, use the widget on sunset.now or browse our guides section.
One common misconception is that blue hour is exactly one hour long. In reality, it rarely lasts that long, except at very high latitudes during certain times of year. The term “blue hour” is somewhat poetic, like “golden hour” — it describes a mood rather than a precise duration. The best way to know exactly when blue hour starts and ends in your city is to check sunset.now daily.
How to Photograph Blue Hour: Pro Tips
Blue hour photography can produce stunning results, but it requires some know-how. First, always use a tripod. Because blue hour is twilight, the light is dim, and you’ll need longer exposures (often 1 to 15 seconds) to capture enough light. A tripod keeps your camera steady and avoids blur. Second, shoot in RAW format to give yourself flexibility when adjusting white balance later. Blue hour light is naturally cool, but you may want to tweak the temperature in post.
Start shooting a few minutes before blue hour officially begins. This gives you time to set up and capture the transition from golden hour to blue hour, which can produce beautiful gradients. For more in-depth camera settings and composition advice, visit what-is-the-blue-hour-for-photographers and best-time-of-day-for-photos. And don’t forget golden-hour-for-weddings if you’re planning a romantic shoot.
Blue Hour Around the World: Variations and Highlights
The experience of blue hour varies dramatically depending on where you are. In northern cities like Reykjavik or Stockholm, blue hour can last nearly an hour in winter, while in summer it may be almost nonexistent due to the midnight sun. Read about midnight-sun-explained for more on high-latitude phenomena. In contrast, near the equator, blue hour is short and consistent year-round, lasting about 20 minutes.
If you’re planning a trip to capture blue hour, consider the best-cities-to-watch-the-sunset-usa for iconic skylines. For coastal shoots, check out sunset-on-the-beach-tips. And if you’re curious about how weather affects the colour, see how-clouds-affect-sunsets and sunset-and-air-quality. The key is to always check the exact blue hour times on sunset.now before heading out — the window is narrow, and timing is everything.
Frequently asked questions
Is blue hour always exactly one hour long?
No, blue hour rarely lasts a full hour. It typically lasts between 20 and 40 minutes, though it can be longer at high latitudes. The name “blue hour” is more poetic than precise.
Can you see blue hour every day?
Yes, blue hour occurs twice daily — once before sunrise and once after sunset — as long as the sky is clear. Clouds, fog, and air quality can affect visibility and colour intensity.
What is the best camera setting for blue hour photography?
Use a tripod, shoot in RAW, set ISO to 100–400, aperture to f/8–f/11, and experiment with shutter speeds from 1 to 15 seconds. Manual white balance around 5000K–5500K works well, but adjust as needed.
How is blue hour different from golden hour?
Golden hour happens when the sun is near the horizon (above it) and produces warm, golden light. Blue hour occurs after sunset and before sunrise, when the sun is 4–18 degrees below the horizon, creating cool, deep blue tones.
