In June and July, visitors of Kantishna Roadhouse are often surprised when they go to bed at 10 pm, and the sun is still up and shining. In fact, during the weeks surrounding the Summer solstice, Kantishna experiences almost 24 hours of daylight.
This phenomenon is not unique to Denali National park. During the summer, the farther north you go in Alaska and in other places near the Arctic Circle, the longer the days last. In Kantishna, the longest days technically have about 20 hours of daylight, and 4 hours of civil twilight, which is when the sun has dropped just below the horizon but sky is still brightly lit by the sun.
Why the Days Are Longer In Summer
Our planet does not spin on a completely vertical axis. Instead, Earth spins on an axis of about 23 degrees, which is the primary factor influencing seasons on our planet. During summer in the northern hemisphere, areas above the equator will experience longer days. During the winter, this is flipped, and areas in the northern hemisphere have shorter days. Near the poles of the Earth, these varied lengths of daylight are more extreme. This is why places in the far north like Alaska experience days with 24 hours of sunlight during the summer and virtually no daylight during the winter.
We can observe this from the Earth because the path the sun takes through the sky will change throughout the year. During the spring and fall equinox when it’s light for almost exactly 12 hours, the sun will take a nearly vertical path through the sky. During the winter in places far north, the sun will take a shorter path through the sky, just peeking above the horizon for a few short hours. During the summer in places far north, the sun will take a long path, seemingly skimming around the horizon for the entire length of the day.
How This Affects the Animals
These varied days play a big role on wildlife in areas near the Arctic Circle. Many larger mammals like bears will forage for food during the late summer and fall and hibernate during the cold winter months. Other animals including many species of birds will migrate south for the winter to avoid harsh months with limited daylight and inclement weather.
Land of the Midnight Sun
Since the sun does not completely set during the summer months, many places near the Arctic Circle are often called the Land of the Midnight Sun. Depending on the location, the sun may not completely dip below the horizon, and sunlight may continue to light up the sky. The sunset and sunrise can merge into a single natural phenomenon. If you’re visiting Kantishna during these summer months, it’s occasionally even possible to catch a glimpse of the mountain during the midnight hour in Denali National Park.