Calculate sunrise and sunset times in your browser with XConvert’s Sunrise Sunset Calculator tool.
37.7749, -122.4194 for San Francisco). Southern latitudes and western longitudes are negative. You can copy coordinates straight from Google Maps by right-clicking any point on the map.Sunrise and sunset times power schedules across photography, aviation, agriculture, religion, and outdoor recreation, and they shift more than people realize: in the contiguous US, day length varies by roughly 6 hours between June and December solstices. A precise per-location, per-date calculation beats rounding to "around 6 a.m." for any planning that depends on light.
The US Naval Observatory and National Weather Service share the same definitions. Sun angle is measured from the geometric center of the Sun to the horizontal plane through the observer.
| Phase | Sun's position | Sky conditions | Used by |
|---|---|---|---|
| Sunrise / sunset | Upper limb on horizon (center 0.833° below) | Direct sun visible; standard horizontal refraction 34 arcmin + solar radius 16 arcmin = 50 arcmin total dip | Everyday clock times, civil schedules |
| Golden hour | 6° below to 6° above horizon | Warm, low-angle direct light | Photography, cinematography |
| Civil twilight | Center 0–6° below horizon | Brightest stars visible; horizon and terrestrial objects clear; artificial light usually not needed | FAA "night" boundary, legal sunset for many statutes |
| Blue hour | Center ~4–6° below horizon | Diffuse blue sky, no direct sun, city lights mix with ambient | Cityscape and travel photography |
| Nautical twilight | Center 6–12° below horizon | Horizon faint; navigation stars visible; outdoor work needs lighting | Celestial sextant navigation, military planning |
| Astronomical twilight | Center 12–18° below horizon | Sky dark enough for naked-eye faint stars; horizon invisible | Astronomy, astrophotography, meteor observation |
| Night | Center >18° below horizon | Full darkness (where geographically possible) | Deep-sky imaging, satellite-pass spotting |
Above the Arctic Circle (currently 66°33′50.9″ N, drifting north about 14.5 m per year due to Earth's nutating axial tilt) and below the Antarctic Circle, the Sun fails to rise or fails to set on at least one day per year. The deeper into the polar region you go, the longer the continuous day or continuous night.
| Latitude band | Phenomenon at solstice | What you see |
|---|---|---|
| 66°34′ to ~67°24′ | One 24-hour day (Jun) / one 24-hour night (Dec) | Sun grazes the horizon at midnight or noon — brief and atmospheric refraction extends it |
| ~67°24′ to ~72°34′ | Civil polar night in winter | Midday looks like late twilight; outdoor work doable without lamps |
| ~72°34′ to ~78°34′ | Nautical polar night in winter | Horizon faint at midday; navigation by stars possible |
| ~78°34′ to ~84°34′ | Astronomical polar night in winter | Naked-eye faint stars visible at midday |
| >84°34′ (Alert, Nunavut at 82.5°N is the limit of permanent settlement) | True polar night | Continuous full darkness for weeks; even 6th-magnitude stars at "noon" |
The 0.833° refraction-and-radius offset means the Sun appears to rise and set slightly outside the geometric Arctic Circle — which is why Tromsø (69.6°N) sees the Sun for a sliver longer in winter than pure geometry predicts.
Three reasons. First, the standard calculation uses a fixed atmospheric refraction of 34 arcminutes; real refraction varies with temperature, pressure, and humidity by up to a few arcminutes, which can shift the apparent horizon time by 30–90 seconds. Second, terrain matters — if you have a mountain to your east, the Sun crests it later than the geometric horizon predicts. Third, most online tables give the time the Sun's upper limb meets the geometric sea-level horizon for your latitude/longitude; an observer on a hilltop or a coastal cliff sees a measurably earlier sunrise because their horizon is geometrically lower. NOAA's solar calculator quotes accuracy "within one minute" between ±72° latitude and "within 10 minutes" outside that band for the same reasons.
The equation of time is the difference between apparent solar time (where the Sun actually is in the sky) and mean solar time (the smooth clock that averages out Earth's elliptical orbit and axial tilt). It ranges roughly from −14 minutes in mid-February to +16 minutes in early November and is zero four times a year. Sunrise and sunset clock times shift accordingly: the latest sunrise in the Northern Hemisphere isn't the winter solstice (Dec 21) but early January, and the earliest sunset is in early December — both displaced by the equation of time. The calculator handles this internally via Jean Meeus's algorithm; you just see the corrected clock time.
Yes. Solar events are computed in UTC from astronomical first principles, then converted to your selected time zone — and if that zone observes DST on the date you picked, an hour is added or removed appropriately. The Sun itself doesn't care about DST; only the clock label changes. If you want to see "wall-clock sunrise minus 1 hour" effects (for example, to confirm that DST really does push evening light later), toggle the zone between standard and daylight versions of the same offset.
Sunrise is the moment the upper edge of the Sun's disc touches the eastern horizon (Sun's center 0.833° below the horizontal). "First light" is colloquial and usually means the start of civil twilight — when the sky is light enough to see without a headlamp, sun center 6° below horizon. At 40° latitude in summer, that gap is about 30 minutes; in winter, closer to 35 minutes. Hunting and aviation regulations often hinge on whichever definition the writing legislator chose, so check the rule, not the colloquialism.
Browser-side sunrise calculators almost universally use Jean Meeus's "Astronomical Algorithms" (1991), the same source NOAA's public calculator and most open-source libraries (suncalc, astral, PyEphem's high-precision mode) cite. Meeus's procedure computes solar declination and right ascension from Julian Day, applies the equation of time, then solves the standard hour-angle equation cos(H₀) = −tan(φ)·tan(δ) with the 0.833° atmospheric-refraction-plus-solar-radius offset. NREL's Solar Position Algorithm (SPA) is more accurate (±0.0003°) but much heavier, used by research-grade solar energy modeling rather than web calculators.
Because of the equation of time. The solstice (around December 21 in the Northern Hemisphere) is the shortest day, but the asymmetry of the equation-of-time curve around it means sunset bottoms out about two weeks earlier (early December) and sunrise bottoms out about two weeks later (early January). Total daylight is still shortest on the solstice — it's just the split between morning and evening darkness that shifts. At 40°N the gap is roughly ±10 days; closer to the equator the offset shrinks, closer to the polar circles it grows.
Standard algorithms degrade above about 72° latitude. The reason is that the Sun crosses the horizon at a very shallow angle near polar regions, so a tiny error in declination or refraction translates to large minutes of clock error. NOAA explicitly warns of "within 10 minutes" accuracy beyond ±72°, and atmospheric refraction over cold polar air can deviate from the standard 34-arcminute value by several arcminutes in either direction, occasionally producing famous mirages like the "Novaya Zemlya effect" where the Sun appears days before it geometrically should. For polar work, consult a local meteorology service or use refraction-corrected almanac data.
Yes — sunrise/sunset/twilight times are exactly what you need for both. For solar energy yield, day length and the equation of time set the practical daily generation window; the calculator's solar-noon output gives the peak generation time. For astrophotography, the end of astronomical twilight defines when long exposures of faint targets become viable, and the start of astronomical dawn defines your deadline. Pair it with a separate moonrise/moonset tool to factor in lunar interference — a 25%-illuminated Moon in your target field will wash out anything below magnitude 12.
Because of the same 0.833° refraction-and-radius offset. The Arctic Circle is the geometric latitude (currently 66°33′50.9″ N) where the Sun's center would theoretically stay above the horizon for exactly one 24-hour period at the summer solstice. But refraction bends light from the Sun over the horizon, and the rim of the Sun (not the center) defines sunrise/sunset for clock times — so people standing on the geographic Arctic Circle actually see the Sun above the horizon continuously for roughly 60 hours straddling the June solstice. The "true" midnight-sun line sits closer to 65°44′ N.