Sunrise and sunset for sixteen cities, on any date
Sunrise, sunset, solar noon and day length for sixteen cities on any date, computed from the NOAA solar algorithm and shown in each city's own clock time.
Local clock times for each city. Sunrise and sunset are when the upper limb of the Sun touches the horizon, which is 0.833° earlier and later than the center crossing it — 34′ of refraction and 16′ of the Sun's own radius.
| City | Sunrise | Solar noon | Sunset | Day length |
|---|---|---|---|---|
| New York · United States | 06:28 | 11:39 | 16:50 | 10h 22m |
| Chicago · United States | 06:25 | 11:34 | 16:42 | 10h 18m |
| Denver · United States | 06:30 | 11:43 | 16:56 | 10h 25m |
| Los Angeles · United States | 06:14 | 11:36 | 16:58 | 10h 44m |
| Honolulu · United States | 06:35 | 12:14 | 17:54 | 11h 19m |
| Anchorage · United States | 08:33 | 12:43 | 16:53 | 8h 20m |
| Mexico City · Mexico | 06:38 | 12:20 | 18:01 | 11h 24m |
| São Paulo · Brazil | 05:19 | 11:50 | 18:20 | 13h 01m |
| London · United Kingdom | 06:56 | 11:44 | 16:31 | 9h 34m |
| Reykjavík · Iceland | 09:16 | 13:11 | 17:06 | 7h 50m |
| Tromsø · Norway | 08:18 | 11:27 | 14:36 | 6h 18m |
| Cape Town · South Africa | 05:44 | 12:29 | 19:15 | 13h 31m |
| Nairobi · Kenya | 06:11 | 12:16 | 18:21 | 12h 10m |
| Singapore · Singapore | 06:46 | 12:48 | 18:50 | 12h 04m |
| Sydney · Australia | 05:53 | 12:38 | 19:23 | 13h 31m |
| Longyearbyen · Svalbard, Norway | does not rise | 11:40 | does not rise | — |
Solar noon is when the Sun crosses the meridian — its highest point. It is almost never 12:00 on a clock: the offset comes from the city's longitude within its time zone, and from the equation of time, which reaches about ±16 minutes over the year.
Sunrise and sunset are not when the center of the Sun crosses the horizon. They are when the upper limb does, and the Sun is already 0.833° above the geometric horizon by then — 34 arcminutes of atmospheric refraction plus 16 arcminutes of the Sun’s own radius. That single convention is why the day is longer than twelve hours at the equinox, and why a table that ignores it disagrees with the sky by six or seven minutes.
The table above computes it the way the NOAA solar calculator does, then prints each city’s times in that city’s own clock — including daylight saving, because the offsets come from the IANA time zone database rather than a stored number.
What each column means
Solar noon is the moment the Sun crosses the meridian: its highest point, and the midpoint between sunrise and sunset. It is rarely 12:00 on a clock, and the gap has two separate causes. A city sits somewhere inside its time zone, up to half a zone width from the zone’s central meridian, which in a wide zone is worth 30 minutes. On top of that the equation of time runs from about −14 minutes in February to +16 minutes in early November, because Earth’s orbit is an ellipse and its axis is tilted.
Day length is sunset minus sunrise, so it inherits the 0.833° convention: it is always slightly longer than the geometric half-day doubled.
The polar rows
Inside the Arctic and Antarctic circles the Sun can fail to rise or fail to set for months, and the tool says so in words rather than printing a time it cannot justify. Longyearbyen, at 78°N, is included as the example: continuous daylight from about April 19 to August 23, continuous darkness from about October 26 to February 15.
There is a second, subtler edge a rise/set table usually hides: between the polar night and the first real sunrise there are days when the Sun climbs above the horizon for only a few minutes, around local noon. The algorithm still returns a time for those days — a short day, not a missing one.
Where the accuracy stops
The NOAA method is good to about a minute at mid-latitudes, and that ceiling is why this page prints minutes and never seconds. It also assumes a level sea horizon and standard refraction. On a hilltop you see the Sun before the table says; in a deep valley you see it after. A cold, dense lower atmosphere refracts more than 34 arcminutes and lengthens the day at both ends.
The calculation is checked against the USNO’s tables for every city in the list, and the residuals are
printed by npm run verify-sky in the site’s repository rather than asserted here.
If the question behind the question is “why does the earliest sunset come before the shortest day”, that is a different effect with its own explanation; and if it is “why is the day longer than twelve hours at the equinox”, the equinox page takes it apart.
These are computed astronomical times for a standard horizon. They are not a substitute for a local almanac where terrain matters.
Frequently asked questions
- Why is the equinox not exactly twelve hours of daylight?
- Because sunrise and sunset are defined on the upper limb of the Sun, not its center. Refraction lifts the Sun about 34 arcminutes above where it geometrically is, and the disc itself is about 16 arcminutes across, so the Sun appears above the horizon for roughly 50 arcminutes beyond the geometric half-day. At the equator that is about seven extra minutes; at higher latitudes it is more, because the Sun crosses the horizon at a shallower angle.
- Why is solar noon almost never 12:00?
- Two reasons, and they add. The city's longitude sits somewhere within its time zone, up to half a zone width from the meridian the zone is named for — that alone is up to 30 minutes. And the equation of time, the difference between apparent and mean solar time, swings between about −14 and +16 minutes over the year because Earth's orbit is elliptical and its axis is tilted.
- What happens above the Arctic Circle?
- The Sun stops crossing the horizon. Longyearbyen has continuous daylight from roughly April 19 to August 23 and continuous darkness from roughly October 26 to February 15. The tool prints "does not set" or "does not rise" rather than a time, because there is no time to print.
- How accurate are these times?
- To about a minute at mid-latitudes, which is the documented accuracy of the NOAA algorithm: it uses a truncated solar position rather than a full ephemeris. It also assumes a sea horizon and standard refraction of 34 arcminutes, so a hill, a building or an unusually warm or cold lower atmosphere will move the observed time by more than the calculation's own error.
Sources
- NOAA Global Monitoring Laboratory, Solar Calculator — the sunrise/sunset algorithm implemented in src/lib/sky.mjs, including the 90.833° zenith that folds in refraction and the solar semi-diameter (gml.noaa.gov/grad/solcalc/)
- U.S. Naval Observatory, Astronomical Applications Department — Rise/Set/Twilight tables, used to cross-check the computed times city by city and date by date (aa.usno.navy.mil/data/RS_OneDay)
- Meeus, Astronomical Algorithms, 2nd edition, chapter 25 — apparent solar longitude and the equation of time behind the solar-noon figure
- National Weather Service, Astronomical Data — the standard 34-arcminute refraction at the horizon and the definition of sunrise and sunset on the upper limb