Sun Exposure in Switzerland: Sun Path, Winter Shadow, and What It Means for Your Property

How much sun a place actually gets depends not just on the date, but on the mountains, hills and buildings on its horizon. This page explains how sun exposure works in Switzerland – and how to actually calculate it for a specific address instead of guessing.

What sun exposure actually is

Sun exposure is the time a location actually receives direct sunlight – not the time the sun is somewhere in the sky. The difference comes from the horizon: mountains, hills, forests and neighbouring buildings often block the sun hours before or after it rises or sets astronomically. In Switzerland, with its pronounced topography, that difference can be large – in some valleys the winter sun doesn't reach a location until hours after astronomical sunrise, if at all.

Why a plain sun-position calculator isn't enough

Most free sun-path tools show only the astronomical sun position – the sun's path over a flat, open horizon. That's useful, but says little about what actually happens at a specific location. Suntag calculates using Switzerland's real terrain model – a 25-metre elevation grid published by swisstopo – and traces the horizon in every direction from your point. The result isn't the theoretical sun position, but the actual sun exposure: when the sun clears the surrounding hills and mountains, day by day, across the whole year.

Daylight duration through the year

Day length in Switzerland varies sharply, due to its position on the 47th parallel, similar to Montreal or Novosibirsk. Reference values for the Zurich area:

21 December (winter solstice)8h 24min
Early February / early November~9h 30min
20 March / 23 September (equinoxes)~12h 10min
Early May / early August~14h 30min
21 June (summer solstice)16h 10min

Orientation and sun exposure

A property's orientation determines what time of day it gets sun:

SouthSun all day from midday, maximum exposure
SouthwestAfternoon and evening sun
SoutheastMorning and midday sun
WestEvening sun only, can get hot in summer
EastMorning sun only
NorthLittle to no direct sun

South- and southwest-facing properties are sought-after in the Swiss market and are routinely valued positively in appraisals; a purely north-facing property with no direct sun tends to work the other way.

The winter-shadow rule

On 21 December, the sun in Switzerland sits only about 19° above the horizon. At that shallow angle, a 10-metre building casts a midday shadow of roughly 29 metres. In summer, when the sun climbs to 66°, that's only about 4.5 metres – in spring and autumn, around 11 metres. So at a viewing, don't just ask "does the sun reach this room?" – ask "what's within 30 metres to the south?" Any building or large tree there can take your winter sun.

What to check at a viewing

  1. Visit in winter if you can, between November and February – in summer, almost every location has enough light.
  2. Check within 30 metres to the south for buildings, trees or hills.
  3. Ask about the orientation of the living spaces, not just the address.
  4. Higher floors usually get more sun, since less of the surroundings block the horizon.
  5. Don't rely on a single viewing on one sunny day.

Calculate the sun exposure for your own address

The Suntag report calculates real sun exposure for any address in Switzerland and Liechtenstein, day by day across the whole year, based on the real terrain model from swisstopo. It also covers road and rail noise, public-transport access, fibre and 5G – a 16-page PDF report from CHF 12.

Calculate now

Frequently asked questions about sun exposure

What's the difference between sun exposure and sunshine?

Sunshine describes whether the sun is shining in the sky or hidden by clouds – a weather question. Sun exposure describes whether the sun could be visible at a given location at all, given the horizon formed by mountains, hills and buildings – a geometry question, independent of the weather.

How much does sun exposure vary by season in Switzerland?

Significantly. Daylight duration ranges from about 8h 24min on 21 December to 16h 10min on 21 June, and the maximum sun height from only ~19° in winter to ~66° in summer. Because the winter sun sits so low, it's blocked far more easily by terrain or buildings than the high summer sun.

Why does sun exposure matter more in winter than in summer?

Because in summer almost every location gets enough direct sun – the difference between good and poor locations only shows up in winter, when the low sun is easily blocked by neighbouring buildings, trees or hills. A winter viewing therefore reveals more than a summer one.

Can I get sun exposure calculated for a specific address?

Yes. The Suntag report calculates real sun exposure for any address in Switzerland and Liechtenstein, day by day across the whole year, based on the real terrain model from swisstopo – not just the astronomical sun position. The 16-page PDF report costs CHF 12 and is ready within seconds.

How does sun exposure affect heating costs and comfort?

Good sun exposure lets more solar warmth into living spaces in winter, which can noticeably cut heating demand – an effect known as passive solar gain. A purely north-facing property with no direct sun tends to mean higher heating costs and a cooler, darker feel, especially in the winter months.

Sources and methodology: Calculation basis: Switzerland's 25-metre terrain model from swisstopo, combined with the astronomical sun path. The values shown on this page (daylight duration, sun height, shadow length) are general astronomical reference values for Switzerland (reference latitude approx. 47.4° N, Zurich area) and can vary slightly by exact location. For the actual sun exposure of a specific address, the Suntag report calculates that address's individual horizon.