Finding a city that never gets dark may seem like an impossible task. After all, night time comes to every place on Earth at some point during a 24-hour cycle. However, there are a few cities in the world that come close to never experiencing nighttime due to their extreme northern locations inside the Arctic Circle. These cities have periods called “polar days” in the summer where the sun does not fully set below the horizon, and “polar nights” in the winter where the sun does not rise. So while no city literally stays illuminated 24 hours a day, 365 days a year, some cities do technically never see a fully dark night during certain seasons.
What causes polar days and polar nights?
The reason that cities inside the Arctic Circle can experience days or nights where the sun does not fully set or rise is because of the tilt of Earth’s axis. Earth is tilted 23.5 degrees relative to the plane of its orbit around the sun. This tilt means that during the summer months in the Northern Hemisphere, locations inside the Arctic Circle are angled towards the sun even as the Earth rotates. The sun never drops fully below the horizon, so there is no night time. The opposite occurs in the winter months – the Northern Hemisphere is angled away from the sun so locations inside the Arctic Circle never see the sun come over the horizon at all. The exact dates of polar days and polar nights depend on how far north the location is.
What cities have polar days?
There are a several cities and towns inside the Arctic Circle that experience summer polar days when the sun remains visible for 24 hours:
- Hammerfest, Norway – from May 15 to July 28
- Rovaniemi, Finland – from June 3 to July 7
- Murmansk, Russia – from May 22 to July 22
- Reykjavik, Iceland – from June 2 to July 28
- Tromsø, Norway – from May 20 to July 22
- Unalaska, Alaska, USA – from May 10 to August 2
Of these cities, Hammerfest, Norway remains illuminated by the sun the longest – for over two straight months from mid-May to late July. So in the middle of summer, this city experiences no true nighttime.
What is life like during polar days?
Living in a city with polar days can be an unusual experience. With the sun always visible, residents experience a sort of “endless daylight” during the summer months. Some key aspects of life in a polar day city include:
- Sleep disruption – rooms never get fully dark, making it hard to sleep
- Eye masks for sleeping – many residents use eye masks to block out sunlight
- No electricity savings – little or no chance to save on electric lights during summer
- Increased activity – more people stay active late at night with daylight
- Lower crime rates – continuous daylight provides added safety
While the endless daylight can take some getting used to, many polar cities also have a bustling nightlife scene in the summer because residents and tourists take advantage of the unique ability to be out and about at all hours of the “day.” For many living in polar regions, the long periods of daylight provide a unique summertime lifestyle.
Compare: Polar day vs. Polar night
Cities inside the Arctic Circle experience polar days in the summer, when the sun remains visible for a 24 hour period, as well as polar nights in the winter, when the sun does not rise at all. Here is a comparison:
| Polar Day | Polar Night |
|---|---|
| Occurs in summer months | Occurs in winter months |
| Sun always above horizon | Sun always below horizon |
| No true nighttime | No true daytime |
| Increased human activity | Decreased human activity |
| Lower crime rates | Higher rates of depression |
So in many ways, life is reversed between the summer and winter months in Arctic cities. Endless daylight switches to endless darkness before repeating the cycle.
Human health impacts
Living in a city with polar days or polar nights can have some impacts on human health, including:
Circadian rhythm disruption
The circadian rhythm, or natural human wake/sleep cycle, becomes disrupted without normal daylight/nighttime cues. Lack of darkness disturbs the body’s production of melatonin and testosterone.
Increased tiredness
Despite more daylight hours, exhaustion and tiredness are common in polar day cities as people struggle to sleep well. Fatigue sets in.
Altered brain chemistry
Serotonin levels can be impacted by constant sunlight exposure. This can increase anxiety, irritability, and seasonal depression.
Vitamin D deficiency
Lack of sunlight in the winter polar nights reduces people’s vitamin D absorption, leaving them deficient.
There are also some possible health benefits, like improved mood and concentration from extra daylight during polar days. But the circadian disruptions are known to be detrimental overall if not properly managed.
Managing life in polar day cities
People living in polar day cities have to come up with strategies to manage the unique lifestyle:
Using blackout curtains
Blackout curtains or window shades help block constant daylight to create artificial darkness for sleeping during summer.
Taking melatonin supplements
Melatonin tablets help reset the body’s circadian clock and promote sleep in the absence of nighttime.
Using eye masks and earplugs
Masking both sound and light can improve the sleep environment.
Scheduling sleep and social time
Planning sleep schedules and social activities helps provide structure.
Using vitamin D supplements
Vitamin D supplements during the winter polar nights boost deficient levels.
Using daylight simulation lamps
Special sunlight lamps provide brightness and vitamin D during the dark winters.
Conclusion
No city literally remains illuminated 24 hours a day, 365 days a year. But thanks to the unique tilt of Earth’s axis, cities inside the Arctic Circle experience periods where the sun does not fully set or rise. Hammerfest, Norway is considered the polar day capital of the world, remaining bright for over two months in the summer without nightfall. These endless daylight hours create an unusual summertime lifestyle for residents. Staying healthy requires following strategies like using blackout curtains and taking melatonin to maintain proper circadian rhythms. While the polar night winters also provide challenges, the rare midnight sun remains a special phenomenon cherished by Arctic city residents each summer.