Polar night in the context of "McMurdo Station"

Lapland is the largest and northernmost region of Finland. The 21 municipalities in the region cooperate in a Regional Council. Lapland borders the Finnish region of North Ostrobothnia in the south. It also borders the Gulf of Bothnia, Norrbotten County in Sweden, Finnmark County and Troms County in Norway, and Murmansk Oblast and the Republic of Karelia in Russia. The topography of Lapland varies from vast mires and forests in the south to fells in the north. The Arctic Circle crosses Lapland, so polar phenomena such as the midnight sun and polar night can be viewed in this region.

Lapland's cold and wintry climate, coupled with its relative abundance of conifer trees such as pines and spruces, means that it has become associated with Christmas in some countries, most notably the United Kingdom, and holidays to Lapland are common towards the end of the year. However, the Lapland region has developed its infrastructure for year-round tourism. For example, in 2019, tourism during the snow-free period grew more than in the winter season. In recent years, Lapland has also become a major tourist destination for celebrities as well as royalty.

The winter solstice, or hibernal solstice, occurs when either of Earth's poles reaches its maximum tilt away from the Sun. This happens twice yearly, once in each hemisphere (Northern and Southern). For that hemisphere, the winter solstice is the day with the shortest period of daylight and longest night of the year, and when the Sun is at its lowest daily maximum elevation in the sky. Each polar region experiences continuous darkness or twilight around its winter solstice. The opposite event is the summer solstice.

The winter solstice occurs during the hemisphere's winter. In the Northern Hemisphere, this is the December solstice (December 21 or 22) and in the Southern Hemisphere, this is the June solstice (June 20 or 21). Although the winter solstice itself lasts only a moment, the term also refers to the day on which it occurs. Traditionally, in many temperate regions, the winter solstice is seen as the middle of winter; "midwinter" is another name for the winter solstice, although it carries other meanings as well. Other names are the "extreme of winter", or the "shortest day".

The Arctic Circle is one of the two polar circles, and the northernmost of the five major circles of latitude as shown on maps of Earth at about 66° 34' N. Its southern counterpart is the Antarctic Circle.

The Arctic Circle marks the southernmost latitude for which at the December solstice (winter) the Sun does not rise and at the June solstice (summer) the Sun does not set. These phenomena are referred to as polar night and midnight sun, respectively, and the closer to the pole one goes, the longer that situation persists. For example, in the Russian port city of Murmansk (three degrees north of the Arctic Circle) the Sun stays below the horizon for 20 days before and after the winter solstice, and above the horizon for 20 days before and after the summer solstice.

Ramadan is the ninth month of the Islamic calendar. It is observed by Muslims worldwide as a month of fasting (sawm), communal prayer (salah), reflection, and community. It is also the month in which the Quran is believed to have been revealed to the Islamic prophet Muhammad. The annual observance of Ramadan is regarded as one of the five pillars of Islam and lasts twenty-nine to thirty days, from one sighting of the crescent moon to the next.

Fasting from dawn to sunset is obligatory (fard) for all adult Muslims who are not acutely or chronically ill, travelling, elderly, breastfeeding, pregnant, or menstruating. The predawn meal is referred to as suhur, and the nightly feast that breaks the fast is called iftar. Although rulings (fatawa) have been issued declaring that Muslims who live in regions with a midnight sun or polar night should follow the timetable of Mecca, it is common practice to follow the timetable of the closest country in which night can be distinguished from day.

The stratosphere is the second-lowest layer of the atmosphere of Earth, located above the troposphere and below the mesosphere. Pronounced /ˈstrætəˌsfɪər, -toʊ-/, the name originates from from Ancient Greek στρωτός (strōtós) 'layer, stratum' and -sphere. The stratosphere is composed of stratified temperature zones, with the warmer layers of air located higher (closer to outer space) and the cooler layers lower (closer to the planetary surface of the Earth). The increase of temperature with altitude is a result of the absorption of the Sun's ultraviolet (UV) radiation by the ozone layer, where ozone is exothermically photolyzed into oxygen in a cyclical fashion. This temperature inversion is in contrast to the troposphere, where temperature decreases with altitude, and between the troposphere and stratosphere is the tropopause border that demarcates the beginning of the temperature inversion.

Near the equator, the lower edge of the stratosphere is as high as 20 km (66,000 ft; 12 mi), at mid-latitudes around 10 km (33,000 ft; 6.2 mi), and at the poles about 7 km (23,000 ft; 4.3 mi). Temperatures range from an average of −51 °C (−60 °F; 220 K) near the tropopause to an average of −15 °C (5.0 °F; 260 K) near the mesosphere. Stratospheric temperatures also vary within the stratosphere as the seasons change, reaching particularly low temperatures in the polar night (winter). Winds in the stratosphere can far exceed those in the troposphere, reaching near 60 m/s (220 km/h; 130 mph) in the Southern polar vortex.

Kittilä (Finnish: [ˈkitːilæ]; Northern Sami: Gihttel, Inari Sami: Kittâl, Skolt Sami: Kihttel) is a municipality of Finland and a popular holiday resort. It is located in northern Finland north of the Arctic Circle within the Lapland region. The municipality has a population of 6,658 (30 June 2025) and covers an area of 8,262.97 square kilometres (3,190.35 sq mi) of which 168.71 km (65.14 sq mi) is water. The population density is 0.82 inhabitants per square kilometre (2.1/sq mi).

Kittilä is famous for being the location of the lowest recorded temperature in Finnish history: −51.5 °C (−60.7 °F), measured in January 1999 in Pokka. The "midnight sun" is above the horizon from 29 May to 16 July, and the period with continuous daylight lasts a bit longer, polar night from 14 December to 29 December.

Midnight sun, also known as polar day, is a natural phenomenon that occurs in the summer months in places north of the Arctic Circle or south of the Antarctic Circle, when the Sun remains visible at the local midnight. When midnight sun is seen in the Arctic, the Sun appears to move from left to right. In Antarctica, the equivalent apparent motion is from right to left. This occurs at latitudes ranging from approximately 65°44' to exactly 90° north or south, and does not stop exactly at the Arctic Circle or the Antarctic Circle, due to refraction.

The opposite phenomenon, polar night, occurs in winter, when the Sun stays below the horizon throughout the day.

A polar vortex, more formally a circumpolar vortex, is a large region of cold, rotating air; polar vortices encircle both of Earth's polar regions. Polar vortices also exist on other rotating, low-obliquity planetary bodies. The term polar vortex can be used to describe two distinct phenomena; the stratospheric polar vortex, and the tropospheric polar vortex. The stratospheric and tropospheric polar vortices both rotate in the direction of the Earth's spin, but they are distinct phenomena that have different sizes, structures, seasonal cycles, and impacts on weather.

The stratospheric polar vortex is an area of high-speed, cyclonically rotating winds around 15 km to 50 km high, poleward of 50°, and is strongest in winter. It forms during autumn when Arctic or Antarctic temperatures cool rapidly as the polar night begins. The increased temperature difference between the pole and the tropics causes strong winds, and the Coriolis effect causes the vortex to spin up. The stratospheric polar vortex breaks down during spring as the polar night ends. A sudden stratospheric warming (SSW) is an event that occurs when the stratospheric vortex breaks down during winter, and can have significant impacts on surface weather.