South-facing garden: how much sun it really gets

A south-facing garden is one where you stand at the back door, look down the garden and face south. In the UK that's the sunniest way a garden can point: the house never throws its midday shadow across it, and in June most of the lawn sees 12 hours or more of direct sun.

Opens the Sun hours view on a terraced street in Leicester. Search your own address to check yours.

Which way counts as south-facing

The direction is taken from the back of the house looking out. In UK property listings, "south-facing" almost always describes the garden, so a house with a south-facing garden has a north-facing front door. Open the compass on your phone, stand with your back to the rear wall and read the bearing straight ahead.

Very few gardens point exactly south. One facing south-east trades a little evening sun for more morning sun, and south-west does the opposite. Both behave mostly like south. If you're not sure which way your plot points, the guide to which way your house faces walks through it.

Where the sun goes during the day

The sun is due south at solar noon. In London that's 13:03 BST in late June and 11:59 GMT in late December, not 12 o'clock. Around that time the house's shadow falls on the street side, away from the garden.

Summer mornings and evenings are the odd part. On 21 June the London sun rises at a bearing of 49°, north of east, and sets at 311°, north of west. For the first few hours after sunrise and the last few before sunset it sits behind the house, so the patio right against the back wall only gets sun from about 08:25 to 17:35. Ground further out catches more, because a high summer sun casts a short shadow.

Hours of sun, by season and distance from the house

These figures are for London, treating a two-storey terrace as a long wall 8 m high with nothing else around: no fences, trees or houses behind. They're calculated with SunCalc, the formulas the map uses, in 10-minute steps.

Two things stand out. The back wall gets more sun in March than in June, because the midsummer sun spends so long in the northern half of the sky. And from the equinox to midwinter the house doesn't shade the garden at all, since the sun never leaves the south. So the open-plot figure in winter is simply sunrise to sunset.

The catch is what sits at the bottom of the garden

Real gardens aren't open plots. In winter the sun is low and always in the south, so whatever stands south of you does the shading. Take a 15 m garden that backs onto another 15 m garden, with a second 8 m terrace beyond it, so the two rows of back walls are 30 m apart.

In June that changes almost nothing: the middle of the garden still gets 12.8 hours. By 20 October the far end, 14 m out, is down to 4.2 hours. On 21 December no spot at ground level gets direct sun at all, because at noon the houses behind cast a shadow 29.7 m long. Your upstairs windows still catch it, but the lawn doesn't.

So a south-facing listing tells you about summer. For winter, look at what's behind the back fence. A long garden, low bungalows behind or a wide gap between terraces all help.

South of the equator it's the other way round

In Australia, New Zealand, South Africa and South America the midday sun is in the north. There the sunny garden is the north-facing one: 10 m out from an 8 m house in Sydney, a north-facing garden gets 9.7 hours on 21 June (midwinter) and 11.8 hours on 21 December. A south-facing garden in Sydney behaves much like a north-facing garden in the UK.

Check your own garden

1. Search your address and set the date to 21 June.
2. Switch to Sun hours and tap or hover a spot on the lawn to read its hours of direct sun for that day.
3. Change the date to March and then December and read the same spot again. The winter number is the one a listing won't tell you.

If your garden turns out to face a little east or west of south, the east-facing and west-facing guides cover how the morning and evening light behave.