Sunrise and Sunset Times Calculator
Sunrise and sunset times depend on your latitude, longitude and the date. In London on the June solstice the sun rises at about 4:43 AM and sets at about 9:21 PM, giving roughly 16 hours 38 minutes of daylight.
Calculated with the NOAA solar equations, normally accurate to within about a minute or two away from the poles (less near polar circles). It assumes sea level and a flat horizon, so hills and buildings change what you see.
How sunrise and sunset are calculated
The calculator uses the NOAA solar equations. It works out the sun's declination, which is how far north or south of the equator the sun is overhead that day (about +23.4° in June and −23.4° in December), and the equation of time, a correction of up to 16 minutes because Earth's orbit is slightly oval and tilted.
Solar noon is then set by your longitude, at 4 minutes per degree. Finally the hour angle, calculated from your latitude and the sun's declination, tells how far the sun turns between noon and the horizon. Multiply by 4 minutes per degree and you get sunrise and sunset. The Show the math panel walks through each of these with your numbers.
Why day length changes through the year
Earth's axis is tilted 23.4° from its orbit. In summer your hemisphere leans toward the sun, so the sun climbs higher and stays up longer. In winter it leans away. The effect grows with latitude: near the equator day length barely changes, while inside the polar circles the sun can stay up all day (the midnight sun) or stay below the horizon all day (polar night). The calculator reports both cases.
Day length changes fastest around the equinoxes in March and September, gaining or losing several minutes a day at mid-latitudes, and hardly at all near the solstices. The line under your results shows how today compares with yesterday.
Solar noon and twilight
Solar noon is when the sun is at its highest and due south or north of you. It is usually not 12:00 on the clock because of your time zone, daylight saving time and where you sit in it. Civil twilight is the period before sunrise and after sunset when the sun is less than 6° below the horizon: it is bright enough to see outdoors without artificial light. Astronomers count the day from sunrise when the top edge of the sun appears, which the calculation allows for.
Frequently asked questions
- Why is the earliest sunrise not on the longest day?
- At mid-latitudes the earliest sunrise comes about a week before the summer solstice and the latest sunset about a week after it. This happens because of the equation of time, which shifts solar noon slightly earlier or later through the year.
- How accurate are these sunrise and sunset times?
- Usually within a minute or two away from the polar regions. Height above sea level, hills, buildings and weather change what you actually see.
- What time zone are the results shown in?
- The one selected below the coordinates. Choosing a city sets it automatically, including daylight saving time on the chosen date. If you enter custom coordinates, pick the matching time zone.
- What is the midnight sun?
- In summer, inside the Arctic and Antarctic circles, the sun stays above the horizon for 24 hours. In winter the same places have polar night with no sunrise.