Our lines · 05 of 07

Sun Path

The way the sun crosses the city's sky on the longest day, the equinox and the shortest day, a dot for every hour, the noon sun in the city's colour. Worked out from where the city stands, every city on the same scale, so a northern winter looks as low as it feels.

The sun's three arcs over the city.In 640 cities, on tees, crewnecks, hoodies, prints, framed prints, mugs and stickers.

How the sun is worked out

Sun Path draws the sun's way across the city's sky on 21 June, 20 March and 21 December, worked out from the city's latitude with the NOAA general solar position equations.

Times are solar time: the hour dots count whole hours from the moment the sun is highest, not clock time, which depends on the time zone and daylight saving.

Day lengths include the usual allowance for refraction and the size of the sun's disc (the sun counts as up when its centre is 0.833° below a flat horizon). We round them to five minutes and noon heights to the whole degree: hills, buildings and the weather all move the real numbers a little.

Every city is drawn on the same scale, with a level horizon and the zenith at 90°. Cities in the tropics are shown as domes seen side on, because there the noon sun crosses overhead during the year. North of about 65.7° (and south of −65.7°) the summer sun doesn't set and the winter sun doesn't rise.

No map data is used, so the design carries no map credit.

Everything it comes on

Near you

London, Birmingham UK, Glasgow and more