Why the Sun stops rising (or setting)
Earth’s axis is tilted about 23.5°. Inside the Arctic and Antarctic Circles (~66.5°), that tilt can keep the Sun above the horizon for a full rotation in summer, and below it for a full rotation in winter. The official sunrise definition (upper limb, zenith 90.833°) then has no solution — so a honest table says Polar Day or Polar Night instead of inventing 12:00 AM.
At the Circle itself the effect is brief (Rovaniemi). At 78°N (Longyearbyen) it lasts months. Reykjavík and Anchorage are famous for long summer evenings but still have a sunset every day.
Read the physics in Midnight Sun and Polar Night, then open a city page for live calendars.
Arctic Cities on This Site
| City | Latitude | Polar day | Polar night | 21 Jun | 21 Dec |
|---|---|---|---|---|---|
| Tromsø | 69.6° | May 19, 2026 – Jul 25, 2026 | Jan 1, 2026 – Jan 14, 2026; Nov 28, 2026 – Dec 31, 2026 | Polar Day (24h) | Polar Night (0h) |
| Longyearbyen | 78.2° | Apr 19, 2026 – Aug 24, 2026 | Jan 1, 2026 – Feb 15, 2026; Oct 27, 2026 – Dec 31, 2026 | Polar Day (24h) | Polar Night (0h) |
| Reykjavík | 64.1° | None | None | 21h 8m | 4h 8m |
| Rovaniemi | 66.5° | Jun 7, 2026 – Jul 6, 2026 | None | Polar Day (24h) | 2h 15m |
| Utqiaġvik | 71.3° | May 12, 2026 – Aug 1, 2026 | Jan 1, 2026 – Jan 22, 2026; Nov 20, 2026 – Dec 31, 2026 | Polar Day (24h) | Polar Night (0h) |
| Anchorage | 61.2° | None | None | 19h 22m | 5h 27m |
Polar day/night ranges are inclusive calendar dates in 2026 where official sunrise or sunset does not occur. Civil twilight can still brighten midday during polar night near the Circle.
Open a polar city
Tromsø
Tromsø sits well above the Arctic Circle. For weeks around the June solstice the Sun does not set; around the December solstice it does not rise. Official tables switch to Polar Day and Polar Night instead of clock-time sunrise.
Longyearbyen
Longyearbyen on Svalbard is one of the world’s northernmost towns. Polar day and polar night each last months, not weeks, and the official sunrise field is N/A for much of the year.
Reykjavík
Reykjavík sits just south of the Arctic Circle. The Sun still sets in June, but only for a short, bright night. December days shrink to about four hours on a fixed UTC+0 clock with no daylight saving.
Rovaniemi
Rovaniemi sits on the Arctic Circle — the line where midnight sun begins. Around the June solstice the Sun skims the northern horizon instead of setting; December brings a brief polar-night window.
Utqiaġvik
Utqiaġvik (Barrow) is the northernmost city in the United States. Polar day lasts about two months in summer and polar night about two months in winter — the tables say Polar Day/Night, not a clock time.
Anchorage
Anchorage does not have true midnight sun, but June days stretch past 19 hours and December days shrink under six. It is the accessible high-latitude US metro for extreme day-length swings.