Winterline

{{Short description|False horizon from mountains at dusk}}

{{for|the World War II defensive lines in Italy|Winter Line}}

{{for|the Westworld episode|The Winter Line}}

{{Use dmy dates|date=January 2023}}

Winterline or winter line is the term used to describe the false horizon that is formed at dusk and is visible from certain mountainous parts of the world.{{Cite news|url=https://timesofindia.indiatimes.com/city/dehradun/winterline-beckons-enchanting-riot-of-colours-makes-an-appearance-in-mussoorie-skies/articleshow/71809358.cms|title=Winterline beckons: Enchanting riot of colours makes an appearance in Mussoorie skies | newspaper=The Times of India | first=Anmol | last=Jain | date=30 October 2019 | accessdate=29 January 2023}} The reason for its formation is not clear, but it has been reported that "experts" believe it occurs due to refraction of light when the dust particles, moisture, and smog, rising from the plains below, meet the cooler mountain air, and a 'second horizon' is formed.{{Cite web|url=https://www.himalayan-gypsy.in/this-word-winter-line-means-the-formation-of-a-line-known-as-the-horizon-especially-in-the-winter-season/|title=Winter Line: A Rare-Vivid Phenomenon Of Nature}} It is visible from many places throughout the Himalayas and is very prominent from Mizoram, and Mussoorie and Hilly regions of Uttarakhand and Nahan, Himachal Pradesh in India between October and February, and the local Mussoorie Winterline Carnival is named after the phenomenon.{{Cite web|url=https://timesofindia.indiatimes.com/city/dehradun/tourists-throng-winterline-carnival-landour-mela/articleshow/73011449.cms|title=Tourists throng Winterline carnival, Landour Mela | Dehradun News - Times of India|website=The Times of India}}{{Cite web|url=https://www.dailypioneer.com/2015/state-editions/mussoorie-winterline-festival-from-dec-25.html|title=Mussoorie winterline festival from Dec 25|first=The|last=Pioneer|website=The Pioneer}}{{Cite web|url=https://www.jagran.com/uttarakhand/dehradun-city-winterline-carnival-festival-to-be-begin-in-mussoorie-19872669.html|title=Winterline Carnival festival: विंटरलाइन कार्निवाल के लिए दुल्हन सी सज रही मसूरी|website=Dainik Jagran}} Apart from India, winterline occurs in the Swiss Alps.