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Blue Hour Calculator
Find the exact morning and evening blue hour for any location and any date — the twilight window when the sun sits 4° to 8° below the horizon and the sky turns deep blue. Includes golden hour times, the sun's compass direction, and camera settings guidance for photographers.
Plan your blue hour
Uses your browser's geolocation (coordinates only — nothing is sent anywhere; all math runs on this page).
Morning blue hour
Evening blue hour
Math: standard NOAA solar approximation with geometric sun-center altitude, refined by iteration (accurate to about a minute). Sunrise/sunset use the −0.83° refraction convention; twilight bands use pure geometry. Times are a planning guide — arrive 10–15 minutes early.
How long does the blue hour last? Duration by latitude & season
The blue hour is almost never a full hour. How long it lasts depends on how steeply the sun's path crosses the horizon: near the equator the sun drops almost vertically and races through the 4°–8° band in about 16 minutes, while at high latitudes it slides along at a shallow angle and the window stretches past 40 minutes. Each value below is the length of one blue hour session (morning or evening) for the Blue Hour Site definition (sun −8°…−4°), computed with the same engine as the calculator.
| Latitude | March equinox (20 Mar 2026) | June solstice (21 Jun 2026) | December solstice (21 Dec 2026) |
|---|---|---|---|
| 0° | 16 min | 17.5 min | 17.5 min |
| 10° | 16.2 min | 17.9 min | 17.6 min |
| 20° | 17 min | 19.2 min | 18.5 min |
| 30° | 18.5 min | 21.7 min | 20.2 min |
| 40° | 20.9 min | 26.4 min | 23.2 min |
| 50° | 25 min | 37.6 min | 28.7 min |
| 60° | 32.4 min | — | 40.8 min |
| 66.5° | 41 min | — | 62.6 min |
“—” means no blue hour occurs that day: at 60°N on the June solstice the sun never sinks to 4° below the horizon (white nights). Southern-hemisphere readers: swap the June and December columns.
Worked example: Jakarta, 11 October 2026
Jakarta sits almost on the equator (−6.21°, 106.85°E, Western Indonesia Time, UTC+7), so its blue hours are short and nearly identical year-round. For 11 October 2026 this calculator gives:
- Morning blue hour: 05:04 – 05:20 (16 minutes). Arrive on location by about 04:50 to set up.
- Evening blue hour: 17:58 – 18:14 (16 minutes), starting 13 minutes after the 17:45 sunset.
- Sunrise 05:33, sunset 17:45, solar noon about 11:39.
- Golden hour: 05:20 – 06:00 in the morning, 17:17 – 17:58 in the evening (PhotoPills definition: sun −4°…+6°).
- Sun direction during blue hour: about 97° (just south of due east) in the morning, 263° (just south of due west) in the evening — face the glowing horizon opposite the sunrise/sunset point for the deepest blue.
- With the narrower PhotoPills definition (−6°…−4°) the same day's windows shrink to 05:12 – 05:20 and 17:58 – 18:06 (8 minutes each).
Compare that with London on 21 June 2026: blue hour runs 03:33 – 04:14 and 21:49 – 22:30 — about 41 minutes per session, more than twice Jakarta's window. Latitude is the single biggest lever on blue hour length.
How this calculator works
Every time on this page comes from solar geometry, computed entirely in your browser:
- Solar position (NOAA approximation). For your date we compute the sun's declination and the equation of time, then solve the hour-angle equation for each target altitude. The result is refined by iteration, landing within about a minute of precise ephemerides for everyday planning.
- Altitude bands, honestly labeled. Blue hour (default): sun elevation −8° to −4°, the definition published by the Blue Hour Site. Optional PhotoPills band: −6° to −4°. Golden hour: −4° to +6°, the convention PhotoPills documents for its planner. Civil twilight (−6° to 0°) is shown as a reference row.
- Time zones done right. City presets resolve to IANA time zones, so daylight saving is handled automatically for the date you pick (e.g. London is UTC+1 in June, UTC+0 in December). Custom coordinates use the UTC offset you select.
- Compass direction. The dial shows the sun's azimuth at −6° elevation (the middle of the blue hour), so you know which way to point the camera.
Polar edge cases: above the Arctic/Antarctic circles the sun sometimes never enters the band — midnight sun in summer, polar night in winter. When that happens the calculator says so plainly instead of showing made-up times.
Blue hour camera settings guide
Blue hour light is dim, soft and shadowless — the opposite of harsh midday sun. These are starting points used by working photographers, not rigid rules; check your histogram and adjust.
On a tripod (recommended)
- ISO 100 (your camera's base ISO) for the cleanest files.
- Aperture f/8 to f/11 for landscapes and cityscapes — deep depth of field with sharp optics. Stop down to f/14–f/16 if you want starburst spikes on streetlights.
- Shutter 2 to 30 seconds. Start around 2–4 s early in the window and lengthen to 15–30 s as the sky darkens. Exposures of 8–20 s turn car headlights into light trails and water into glass.
- Focus manually with live-view magnification on a distant light or building edge, then don't touch the ring. Autofocus hunts and misses in this light.
- Turn off image stabilization on the tripod (it can add vibration), and fire with a 2-second timer or remote release.
Handheld (no tripod)
- Open the aperture to f/2.8 or wider, raise ISO to 1600–6400, and keep the shutter at 1/30 s or faster.
- Brace against a wall or railing, shoot in burst mode, and accept some noise — a sharp noisy shot beats a clean blurry one.
Color and exposure
- White balance: manual, 3500–4500 K. Auto white balance tries to “fix” the blue cast — the very color you came for.
- Shoot RAW. White balance and exposure are fully adjustable later with zero penalty.
- Bracket ±1–2 EV when the scene mixes bright windows with dark sky; blend or HDR-merge later.
- Arrive 15–20 minutes before the window starts. Scout compositions in daylight, because you won't be able to see much once it begins.
Related tools (what this is not)
- Sun Angle Calculator — pure solar position math: altitude, azimuth, sunrise/sunset, solar noon, day length and shadows for 37 cities. Use it when you need the astronomy; use this page when you need shootable photography windows.
- Exposure Calculator — the exposure triangle (aperture/shutter/ISO reciprocity) for ambient light in general. This page covers when the blue light happens; that tool covers the math of exposure itself.
- Astrophotography Exposure Calculator — deep-sky settings for when the sun is 12°+ below the horizon. Blue hour is the bright end of twilight; that tool is for true dark sky.
Frequently asked questions
What is the blue hour in photography?
The blue hour is the twilight period just before sunrise and just after sunset when the geometric center of the sun sits between 4 and 8 degrees below the horizon. The sky takes on a deep, saturated blue while streetlights and windows glow warm, which is why cityscapes and landscapes shot then look so striking. This calculator uses the definition published by the Blue Hour Site, one of the earliest dedicated blue hour planners.
When is the blue hour today?
Enter your location and date above. For example, in Jakarta on 11 October 2026 the morning blue hour runs 05:04 to 05:20 and the evening blue hour 17:58 to 18:14 Western Indonesia Time. Times shift every day with latitude and season, so a calculator beats any fixed rule of thumb.
How long does the blue hour last?
It is rarely a full hour. Near the equator each session lasts about 16 to 18 minutes, at 40 degrees latitude about 21 to 26 minutes, and at 60 degrees it can stretch past 30 minutes. In London on 21 June 2026 each blue hour lasts about 41 minutes (03:33 to 04:14 in the morning, 21:49 to 22:30 in the evening). See the duration table above for the full latitude breakdown.
Why do PhotoPills and other planners sometimes show different blue hour times?
They use slightly different definitions. This tool defaults to the Blue Hour Site convention (sun 8 to 4 degrees below the horizon). PhotoPills uses a narrower band (6 to 4 degrees below), which roughly halves the window: for Jakarta on 11 October 2026 the PhotoPills window is 05:12 to 05:20 in the morning, versus 05:04 to 05:20 with the wider definition. Use the definition switcher above to compare both side by side.
What is the difference between blue hour and golden hour?
Golden hour is when the sun is near or just above the horizon, giving warm, directional, golden light. This calculator uses the PhotoPills convention: sun elevation between 4 degrees below and 6 degrees above the horizon. Blue hour follows right after in the evening and comes right before golden hour in the morning: the sun is 4 to 8 degrees below the horizon, direct sunlight is gone, and the sky turns deep blue. Photographers often shoot both back to back.
Is blue hour the same as civil twilight?
Not exactly, but they overlap. Civil twilight is the astronomical term for the sun 0 to 6 degrees below the horizon. Blue hour (8 to 4 degrees below) sits mostly inside civil twilight plus a slice of nautical twilight. This calculator shows civil twilight times as a reference row so you can see the overlap.
What camera settings work best during blue hour?
Blue hour light is dim but even, so a tripod is the single most useful accessory. A common starting point on a tripod: ISO 100, aperture f/8 to f/11, shutter 2 to 30 seconds (shorter early in the window, longer as it darkens). Handheld: open the aperture to f/2.8 or wider, raise ISO to 1600 to 6400, and keep the shutter at 1/30 s or faster. Set white balance manually around 3500 to 4500 K so auto white balance does not wash out the blue, and shoot RAW for maximum flexibility.
What white balance should I use for blue hour?
Manual, between roughly 3500 and 4500 K. Auto white balance tries to neutralize the blue cast, which is exactly the color you want to keep. If you shoot RAW you can fine-tune it later without penalty.
Which direction will the sun be during blue hour?
The sun sits just below the horizon on the sunrise side in the morning and the sunset side in the evening. The calculator shows the exact azimuth for your date and place: for Jakarta on 11 October 2026 it is about 97 degrees (just south of due east) in the morning and 263 degrees (just south of due west) in the evening. Use the compass dial in the results to plan where to stand.
Does the blue hour happen everywhere, every day?
Almost, but there are exceptions near the poles. In Reykjavik on 21 June 2026 the sun never drops to 4 degrees below the horizon, so there is no blue hour at all (the famous white nights). In Tromso on the same date the sun never sets. The calculator reports these cases honestly instead of inventing times.
Why does the blue hour last longer at higher latitudes?
The sun's path meets the horizon at a shallower angle farther from the equator, so it spends more time crossing the 4-to-8-degree band. That is also why the window changes with the seasons: the same latitude gets a longer blue hour in its summer.
Can I shoot blue hour on a cloudy day?
Yes, though the effect is muted. Clouds still reflect the blue twilight glow, and wet streets can add beautiful reflections. Overcast skies lose the gradient but keep the soft, shadowless light. Clear skies give the most saturated blue.
How accurate are these times?
Within about a minute of precise astronomical ephemerides for most locations. The math uses the standard NOAA solar approximation with geometric sun-center altitude, refined by iteration. Atmospheric refraction is negligible at these depths (the 0.83-degree refraction allowance is only applied to the sunrise and sunset reference times). Treat the times as a planning guide and arrive 10 to 15 minutes early.
How is this different from a sunrise-sunset calculator?
A sunrise-sunset tool such as our sun angle calculator reports solar position: altitude, azimuth, sunrise, sunset and day length. This planner is built for photographers: it converts the same astronomy into shootable windows (blue hour, golden hour, civil twilight), the compass direction to face, and exposure guidance. The two complement each other.
Is blue hour useful for astrophotography?
Only as a boundary marker. True dark-sky imaging needs the sun at least 12 to 18 degrees below the horizon (astronomical twilight and night). Blue hour is the bright end of twilight: great for blue-tinted landscapes, cityscapes and moon shots, not for deep-sky targets. See our astrophotography exposure calculator for the dark-sky side.
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