1. Summer Solstice: June 21 marks the official start of summer in Alaska and the rest of the Northern Hemisphere. Known as the Summer Solstice, this is the day when the sun remains visible above the horizon for the longest period of time, and the day is the shortest in the Southern Hemisphere.

2. Indigenous Culture: For Alaska's Indigenous communities, the Summer Solstice has been a significant event for centuries. The day is celebrated as a time of renewal and spiritual growth, with many indigenous communities gathering for traditional ceremonies to mark the occasion.

3. War-time history:  On June 21, 1944, Alaska became the site of one of the deadliest air battles of World War II. The Battle of the Komandorski Islands saw the US Navy defeat Japanese naval forces, which significantly impacted the balance of power in the Pacific theater.

4. Tourism: Alaska's summer tourism industry kicks into high gear in June. Many visitors to the state come during the short summer months to experience the state's natural beauty, wildlife, and adventure opportunities.

5. Environmental Concerns: In recent years, June 21 has become increasingly associated with environmental concerns in Alaska. Melting glaciers, rising sea levels, and eroding coastlines in the state have led to increased calls for environmental protection and action against climate change.