Will I see the sun in December? Winter sunshine in Friuli's mountain villages

Nobody measures these hours on the ground: we computed them, town by town.

• Terrain: the Copernicus GLO-30 elevation model, one point roughly every 30 m, with Austria and Slovenia included.
• Horizon: from each town hall, at eye level, we traced lines in every direction out to 60 km, allowing for the curve of the Earth. The result is the skyline of ridges the village actually sees.
• Sun: its position minute by minute (NOAA's algorithm), for every day of the year. A minute counts as sunny when the top edge of the disc clears the ridge.

We tested the method on a documented case. Viganella, in Piedmont, goes without direct sun for 83 days a year, from 11 November to 2 February, according to its then mayor, quoted by The Sunday Times in 2006; our calculation at two points in the village centre gives 82 and 85. Yet 100 m away the answer ranges from 61 to 105 days. Good enough for a village, not for a single house.

Each dot is a town hall: the paler it is, the less sun on 21 December.

In Claut, in the Friulian Dolomites, the mountain to the south hides the sun for the whole of 21 December. At the town hall there is no direct sun for 14 days running, from 15 December 2026 to 28 December 2026. At the point OpenStreetMap marks as the village centre, a short walk away, the dark spell stretches to 36 days.

The sun comes back fast: 4 h 11 min on 21 January, 7 h 42 min on 21 February. A dark winter, but a short one.

What matters is where the mountain stands, not how high you live. Clauzetto (580 m) and Drenchia (696 m) both get 8 h 32 min of sun on 21 December, close to Udine: nothing to their south blocks the low winter sun, and the terrain costs them just 4 min. Sappada, at 1,242 m, gets 5 h 29 min; Bordano, down on the valley floor at 217 m, 5 h 37 min.

The median mountain town gets 5 h 12 min. These are the ones with the least:

Bordano and Venzone, neighbours in the Gemona area, get almost the same sunshine on 21 December, 5 h 37 min and 5 h 15 min, but at different times. In Bordano the sun arrives at 08:44 and is gone at 14:21, behind the high ground to the south-west, 2.0 km away. In Venzone the mountain to the south-east, 1.2 km off, holds it back until 10:12; then it stays until 15:27. Morning people and afternoon people should not pick the same village.

Gemona, a little further south, gets 7 h 43 min; Tolmezzo 7 h 23 min. Tarvisio is the reverse case: just 3 h 53 min on 21 December, but already 8 h 56 min by 21 February.

We ran the same calculation for 1,140 hamlets in the 102 mountain and inland hill towns: 24 of them lose direct sun for at least one day. The extremes:

• Val Raccolana (Chiusaforte), beneath the north faces of Monte Canin: Tamaroz goes 132 days without sun, Saletto 128.
• Sella Nevea, at the head of the same valley: 43 days.
• Studena Alta (Pontebba): 78 days.

Within one municipality, the slope decides: in Vito d'Asio the hamlet of Chiamp stays in shade all day on 21 December, while the village that gives the municipality its name gets 8 h 32 min of sun.

• One point only: the town hall. 250 m away the hours change: in Gemona from 6 h 31 min to 7 h 56 min, in Forgaria from 2 h 59 min to 8 h 29 min. In 13 towns at least one of those nearby points gets no sun at all on 21 December.
• Clear skies assumed: the model says when the sun's disc is in view, not whether cloud or fog is hiding it.
• Woods: trees and buildings right next to the point are removed, forests on the slopes are not, so a wooded ridge counts slightly higher than bare ground.
• Softened ridges: with one point every 30 m, the shady spell can start or end a few days earlier or later than calculated.