Location
Where 18° 00′ 43″N 65° 35′ 45″E
When 08/20/2012 00:40:38 PDT   (day)
Sunrise 08/19/2012 18:20:48 PDT
Noon 08/20/2012 00:40:38 PDT
Sunset 08/20/2012 07:00:27 PDT
Length 12:39:38
α☉ 9h 59m 33s
δ☉ 12° 16′ 15″
Azimuth 179° 08′ 56″
Elevation 84° 15′ 29″
Air mass 1.0047
Irradiance 946 W/m²
Google Map 18° 00′ 43″N 65° 35′ 45″E

There isn't always a sunrise... near the poles the Sun remains above or below the horizon for months at a time.


At the moment of sunrise, the center of the Sun is actually still below the horizon. Since the Sun as seen from the Earth is about 32 arcminutes wide, we would normally expect to see sunlight when the Sun was 16 arcminutes below the horizon. However right at the horizon, atmospheric refraction will appear to lift it by an additional 34 arcminutes. So we will see the first glimpse of sunlight when the center of the Sun is still 50 arcminutes below the horizon.


At the exact moment of solar noon the Sun will be due North or South, depending on your latitude; an azimuth of either zero or 180 degrees. The calculation we have here should be accurate to within a few seconds of the real solar noon. Note the apparent position of the Sun moves at 15 degrees per hour, which works out to be an arcsecond every 66 milliseconds.