Annual Sunshine evaluates the availability and quality of related facilities and services in each Swiss commune.
Categories: solar_irradiation (100%)
The Annual Sunshine criterion is particularly important for retirees (weight: 80%) and nature lovers (70%). young professionals place less emphasis on it (30%), prioritizing other criteria.
Annual sunshine measures the global solar energy received at ground level over a meteorological reference year, after correction for terrain relief and shading from surrounding mountains, hills, and valleys. VivaMap relies on the solar atlas from the Swiss Federal Office of Energy (SFOE), built on the swissALTI3D digital terrain model at 50 m resolution and MeteoSwiss climate series. The unit is kilowatt-hours per square metre per year (kWh/m²/yr). The normalisation method and score band definitions are described on the methodology page.
Switzerland displays a remarkable solar mosaic. The sunniest regions — Central Valais (Sion, Sierre, Visp), Lower Valais, Ticino (Lugano, Locarno, Bellinzona) — receive more than 2,100 hours of sunshine per year and up to 1,600–1,700 kWh/m² of global irradiation, values comparable to Provence or Tuscany. At the other end, certain deep valleys on the northern Alpine flank or parts of the central Plateau receive only 1,100–1,200 kWh/m², with persistent autumn and winter fog that can cover the sky 60 to 80 days per year.
Exposure (south, east, west) and altitude play a primary role. A commune at 1,000 m elevation with a southern exposure can receive more total irradiation than a lowland commune facing north or shaded by a neighbouring ridge. The Swiss solar atlas integrates this correction at 50 m resolution, capturing significant intra-communal variations — a south-facing facade at 1,200 m can receive 40 to 50% more irradiation than a north-facing facade in the same commune.
Sunshine directly affects several well-being components: mood regulation and prevention of seasonal affective disorder (via vitamin D synthesis and natural light therapy), passive thermal comfort in winter reducing heating costs, and the quality of outdoor spaces (terrace, garden, balcony). Since the 2022 energy crisis, the economic value of sunshine has also been amplified by photovoltaic output — a well-oriented rooftop in a sunny commune can produce 800 to 1,100 kWh/kWp/yr, corresponding to annual savings or revenue of CHF 100 to 200 per kWp installed.
The sunshine score is computed from the median value of the resolution-8 hexagons making up the commune. Intra-communal contrasts can be significant in alpine or Jura communes with pronounced relief. The interactive map allows these nuances to be visualised at neighbourhood or hexagon scale.
Central Valais and Ticino rank among the sunniest regions of central Europe, with irradiation levels matching Northern Spain or the French Mediterranean coast. At the other extreme, the Swiss Plateau endures persistent fog inversions in November–February — a meteorological phenomenon analogous to Baden-Württemberg, Alsace, or the Paris Basin in winter, with annual averages of 1,200–1,300 kWh/m².
On open data, Switzerland stands out for the quality of its national solar atlas at 50 m resolution with swissALTI3D topographic correction — one of the finest in Europe. Germany has the DWD Klimaatlas with irradiation data at kilometre resolution. France publishes its solar atlas via the ADEME and Copernicus SARAH-3 at 2–3 km resolution. The Netherlands, Belgium, and the United Kingdom primarily use the European Commission's PVGIS data (3 km). The 50 m resolution of the Swiss atlas captures local topographic variations — ridges, valleys, shadow zones — that kilometre-scale datasets smooth out entirely. This granularity justifies using this atlas for a score at the H3 hexagon level.
Sunshine exerts a measurable hedonic premium on Swiss and European real-estate markets, with an intensity that has accelerated since the 2022 energy crisis. Swiss property studies converge on a value uplift of 2 to 5% for south-facing dwellings in high-sunshine communes, all else being equal. On an apartment priced at CHF 800,000 in the greater Lausanne or Geneva area, a south-facing orientation with balcony typically commands a premium of CHF 15,000 to 40,000 relative to a north-facing equivalent in the same building.
Since 2022, photovoltaic output has become an explicitly quantifiable financial argument in property transactions. A property with a certified solar installation in a high-sunshine commune (Valais, Ticino) can value that installation at CHF 20,000 to 80,000 depending on peak power and grid-feed-in contracts. Property appraisers are beginning to integrate this potential in valuations for properties with well-exposed roof surfaces. VivaMap makes this potential visible by linking the sunshine score to geographic location — communes scoring 8+/10 in the Alps and the southern Jura offer the best combinations of solar yield and winter quality of life.
On VivaMap's 0–10 scale, here is how to read the sunshine score:
Combine the sunshine score with the transport score to assess the trade-off between winter quality of life and job-centre accessibility: very sunny Valais communes offer exceptional light quality but often require adjustment to a less dense public-transport network than the central Plateau.
Data: FSO, geo.admin.ch, OSM — Scores normalised 0-10