The northernmost city in the United States just had its final sunrise of the season and will experience perpetual daylight for 84 consecutive days. 

Utqiaġvik, Alaska, is located in the Arctic Circle at the very northern tip of the state. Every year, the city with a population of about 4,500 experiences long periods of perpetual daylight during spring and summer months.

On Sunday at 2.57am local time, the sun rose over Utqiaġvik after dipping just below the horizon for about an hour. The city will not experience another sunset until August 2.

The annual period of perpetual daylight is known as the 'midnight sun' or 'a polar day,' according to the National Weather Service. 

All cities, towns and communities in the Arctic Circle experience the phenomenon, as the Earth's tilted axis points the north of the planet towards the sun during this period of the planet's rotation around our star.

Alaska is the only state in the US to experience the midnight sun, but parts of Canada, Greenland, Iceland, Norway, Finland, Sweden and Russia are privy to it as well. 

A camera pointed at the sky recording time-lapse footage in those areas would capture the sun rotating in a circle rather than rising in the east, climbing across the sky and setting in the west, as it does in most parts of the planet. 

Despite the nonstop light, it is expected to remain rather cold in Utqiaġvik throughout the midnight sun period. 

July is typically the warmest month of the year in the region, during which the historical high temperature is still just 49F, according to AccuWeather.

Occasionally, temperatures can climb to around 70F, but it is more common for snowfall to continue through the summer months. Snowflakes were reported on seven days last June, according to Accuweather. 

Once the 84 days of the midnight sun are up, it will still take nearly two months for Utqiaġvik to experience full nighttime darkness. 

Until September 21, 50 days after the August 2 end date of the polar day season, the sun will just dip below the horizon without fully setting. The light conditions at night in Utqiaġvik during those days will thus be akin to an extended dusk.

Other Alaskan cities, such as Fairbanks, have also begun their midnight sun seasons, though none will be as long as that of Utqiaġvik because it is the farthest north. 

Fairbanks will experience 70 days of perpetual sunlight compared to Utqiaġvik's 84.

Anchorage, the largest city in the state, is much further south near the Gulf of Alaska. It will not experience a full midnight sun, though the days will become far longer, stretching 16 to 19 hours.

During the winter, Utqiaġvik and other cities in the Arctic Circle experience a parallel opposite phenomenon, wherein they are plunged into darkness for 64 consecutive days.

That annual period begins with a final sunset on November 18 before the sun finally rises again on January 22 or 23.