Sun elevation and azimuth, explained
The two angles that pin the sun to the sky: what they mean, how they change and how to measure them.
Articles
How the sun moves, and what it means on the ground
Eighteen articles on the questions people ask about the sun: why the earliest sunset is not on the shortest day, which way a garden should face, how long golden hour lasts, where the midnight sun begins. Each one is built on numbers worked out for real places with the same engine that drives the sun position map, and each links to the tool that answers the question for your own location.
New to the map itself? Start with how to read the sun position map. For the formulas behind every number, see method and accuracy.
Angles and time
Angles and time
How the sun’s position is described, and why clocks and sunsets behave the way they do.
Why solar noon is not at 12:00
Time zones, daylight saving and the equation of time: why the sun peaks at 14:16 in Madrid in June.
Why the earliest sunset is not on the shortest day
In London the earliest sunset is 12 December and the latest sunrise 30 December. Here is why.
Where does the sun rise? Sunrise and sunset direction through the year
Due east only near the equinoxes: in London the sunrise point swings 80° along the horizon.
How to find north with the sun and a shadow
The shadow-tip and watch methods can be 20–70° out. The ones that work, and the real errors.
The analemma: why the sun draws a figure eight
Photograph the sun at the same time every week for a year and it traces a lopsided figure eight.
How to calculate the sun’s position: a worked example
Step by step from a date and a place to azimuth and elevation, with every intermediate value for London on 15 October 2026.
Light for photographers
Light for photographers
When the light is warm and low, how long it lasts, and what twilight looks like.
How long does golden hour last?
From under half an hour on the equator to two hours in the north: golden hour by latitude and season.
Civil, nautical and astronomical twilight: how long they last
What each stage of twilight looks like, how long it lasts by latitude and season, and where the night never gets dark.
Home, garden and solar
Home, garden and solar
Sun on walls, gardens and solar panels, worked out in hours and degrees.
Which way should a house, garden or balcony face?
Hours of direct sun on every wall direction, summer and winter, for London and Madrid.
How many hours of direct sun does my garden get?
Full sun, partial shade or shade: hours behind fences and walls of different heights, by season.
Solar panel angle in winter and summer
The best fixed angle, the best summer and winter angles, and what adjusting gains at seven latitudes.
Peak sun hours: how much sunlight does a solar panel get?
Peak sun hours are not hours of sunshine. What they measure, clear-sky values by latitude and month, and how to turn them into kWh.
How long is a shadow at each hour of the day?
Shadow length per metre of height, hour by hour, in summer, at the equinox and in winter, for London and Madrid.
Seasons and latitudes
Seasons and latitudes
Day length, the equinoxes, the tropics where the sun can stand overhead, and the polar regions where it may not set.
When is the sun directly overhead?
Only in the tropics, on one or two days a year: the dates and times for sixteen cities.
Midnight sun and polar night: where and when
How long the sun stays up, or down, in Tromsø, Svalbard, Utqiaġvik, Murmansk and Rovaniemi.
Equal day and night is not on the equinox
On the equinox the day is several minutes longer than the night. When day and night are really equal, city by city.
How day length changes with latitude and season
From twelve hours all year on the equator to 22 hours in June at 65° north: day length by latitude, and how fast it changes.