Sundial
Shade map for any address
Want to know if a café terrace, a park bench or your back garden is in the shade at 3 pm in July? Search the address and drag the clock. The buildings around it cast their shadows as you watch.
Open the shade mapWhat the shade map shows
Sundial draws every building near the address in 3D, using footprints and heights from OpenStreetMap. Then it puts the sun where it really is for that place, date and minute, and renders the shadows. Shaded ground shows up dark and sunlit ground stays bright.
Switch to Sun hours and the map changes. Each patch of ground and roof is coloured by how many hours of direct sun it gets across the day, so you can see the spots that stay shaded the longest.
Why shade moves so much through the year
Shade depends on how high the sun climbs, and that changes a lot between June and December. Here's London at solar noon (calculated with the same formulas the map uses):
| Date | Sun height at noon | Shadow cast by a 10 m building |
|---|---|---|
| 21 June | 61.9° | 5.3 m |
| 20 March / 23 September | 38.4° | 12.7 m |
| 21 December | 15.1° | 37.2 m |
At the December midday a three-storey terrace throws a shadow about seven times as long as it does in June. That's why a garden can be sunny all summer and in shade from October to February. A shade map lets you check this before you buy, rent or plant anything.
Ways people use it
- Gardens. Find the corners that get six or more hours of sun for vegetables, and the shady spots for ferns and hostas. See the south-facing garden guide.
- House hunting. Check whether the living room or the garden of a flat you're viewing will see any winter sun. See north-facing houses.
- Outdoor seating. Pick the side of the square that stays shaded on a hot afternoon, or the pub garden that keeps the evening sun.
- Events and shoots. Plan where the shade will be at the hour you care about, on the actual date.
How to read a spot's shade
- Search the address, or tap the location button to use where you are.
- Set the date, then drag the time slider and watch the shadows sweep across.
- Switch to Sun hours and tap or hover a spot to read its total hours of direct sun for that day.
- Press Share to copy a link that opens on the same place, date and time.
Limits. Building heights come from OpenStreetMap, and where a building has no height the map assumes a typical one. Only individually mapped trees appear, always in full leaf. Hills, cloud and buildings more than 300 m away aren't modelled. Treat it as a good first check, then confirm on site for anything that matters.