Question

why do areas in the arctic circle have 24 hours of daylight on 21 june

Answer 1

At 5:04 UTC (1:04 a.m. EDT) on June 21, the sun can be seen straight overhead along the Tropic of Cancer, while the North Pole reaches its maximum annual tilt toward the sun. As the planet rotates on its axis, areas within the Arctic Circle see the sun circle through the sky for 24 hours